diff --git a/src/grib_accessor_class_g2end_step.cc b/src/grib_accessor_class_g2end_step.cc
index a86733eb3..eed6b5d13 100644
--- a/src/grib_accessor_class_g2end_step.cc
+++ b/src/grib_accessor_class_g2end_step.cc
@@ -262,9 +262,13 @@ static int unpack_one_time_range_long_(grib_accessor* a, long* val, size_t* len)
     }
     if (add_time_range) {
         *val = start_step_value + time_range_value;
+        if ((err = grib_set_long_internal(h, "endStepUnit", step_units)) != GRIB_SUCCESS)
+            return err;
     }
     else {
         *val = start_step_value;
+        if ((err = grib_set_long_internal(h, "endStepUnit", step_units)) != GRIB_SUCCESS)
+            return err;
     }
 
     return GRIB_SUCCESS;
@@ -310,9 +314,13 @@ static int unpack_one_time_range_double_(grib_accessor* a, double *val , size_t*
     }
     if (add_time_range) {
         *val = (start_step + time_range).value<double>(eccodes::Unit(step_units));
+        if ((err = grib_set_long_internal(h, "endStepUnit", step_units)) != GRIB_SUCCESS)
+            return err;
     }
     else {
         *val = start_step.value<double>(eccodes::Unit(start_step_unit));
+        if ((err = grib_set_long_internal(h, "endStepUnit", start_step_unit)) != GRIB_SUCCESS)
+            return err;
     }
 
     return GRIB_SUCCESS;
@@ -441,14 +449,19 @@ static int unpack_long(grib_accessor* a, long* val, size_t* len)
     grib_handle* h = grib_handle_of_accessor(a);
     int ret = 0;
     long start_step_value;
+    long start_step_unit;
     long numberOfTimeRange;
 
     if ((ret = grib_get_long_internal(h, self->start_step_value, &start_step_value)))
         return ret;
+    if ((ret = grib_get_long_internal(h, "startStepUnit", &start_step_unit)))
+        return ret;
 
     /* point in time */
     if (self->year == NULL) {
         *val = start_step_value;
+        if ((ret = grib_set_long_internal(h, "endStepUnit", start_step_unit)))
+            return ret;
         return 0;
     }
 
@@ -479,14 +492,19 @@ static int unpack_double(grib_accessor* a, double* val, size_t* len)
     grib_handle* h = grib_handle_of_accessor(a);
     int ret = 0;
     long start_step_value;
+    long start_step_unit;
     long numberOfTimeRange;
 
     if ((ret = grib_get_long_internal(h, self->start_step_value, &start_step_value)))
         return ret;
+    if ((ret = grib_get_long_internal(h, "startStepUnit", &start_step_unit)))
+        return ret;
 
     /* point in time */
     if (self->year == NULL) {
         *val = start_step_value;
+        if ((ret = grib_set_long_internal(h, "endStepUnit", start_step_unit)))
+            return ret;
         return 0;
     }
 
@@ -542,7 +560,8 @@ static int pack_long_(grib_accessor* a, const long end_step_value, const long en
 
     /*point in time */
     if (self->year == NULL) {
-        err = grib_set_long_internal(h, "startStepUnit", end_step.unit().value<long>());
+        if ((err = grib_set_long_internal(h, "startStepUnit", end_step.unit().value<long>())) != GRIB_SUCCESS)
+            return err;
         err = grib_set_long_internal(h, self->start_step_value, end_step.value<long>());
         return err;
     }
diff --git a/src/grib_accessor_class_optimal_step_units.cc b/src/grib_accessor_class_optimal_step_units.cc
index 494667e9a..d06592e31 100644
--- a/src/grib_accessor_class_optimal_step_units.cc
+++ b/src/grib_accessor_class_optimal_step_units.cc
@@ -178,6 +178,12 @@ static int pack_long(grib_accessor* a, const long* val, size_t* len)
     grib_handle* h = grib_handle_of_accessor(a);
     grib_accessor_optimal_step_units* self = (grib_accessor_optimal_step_units*)a;
 
+    long start_step = 0;
+    long start_step_unit = 0;
+    long end_step = 0;
+    long end_step_unit = 0;
+    int ret;
+
     auto supported_units = eccodes::Unit::list_supported_units();
     try {
         eccodes::Unit unit{*val}; // throws if not supported
@@ -198,10 +204,42 @@ static int pack_long(grib_accessor* a, const long* val, size_t* len)
         return GRIB_INVALID_ARGUMENT;
     }
 
-    int ret;
+    // ECC-1813: When the stepUnits key is used without specifying a value, as in the command
+    // "grib-set -s stepUnits=m in.grib out.grib", the following code initiates an indirect update
+    // of the low-level keys: forecastTime,indicatorOfUnitOfTimeRange,indicatorOfUnitForTimeRange,lengthOfTimeRange
+
     self->overwriteStepUnits = *val;
-    if ((ret = grib_set_long_internal(h, "forceStepUnits", *val)) != GRIB_SUCCESS) {
+    if ((ret = grib_set_long_internal(h, "forceStepUnits", *val)) != GRIB_SUCCESS)
         return ret;
+
+    if ((ret = grib_get_long_internal(h, "startStep", &start_step)) != GRIB_SUCCESS)
+        return ret;
+    if ((ret = grib_get_long_internal(h, "startStepUnit", &start_step_unit)) != GRIB_SUCCESS)
+        return ret;
+    if ((ret = grib_get_long_internal(h, "endStep", &end_step)) != GRIB_SUCCESS)
+        return ret;
+    if ((ret = grib_get_long_internal(h, "endStepUnit", &end_step_unit)) != GRIB_SUCCESS)
+        return ret;
+
+    try {
+        eccodes::Step start{start_step, start_step_unit};
+        start.set_unit(*val);
+        eccodes::Step end{end_step, end_step_unit};
+        end.set_unit(*val);
+
+        if ((ret = grib_set_long_internal(h, "startStepUnit", start.unit().value<long>())) != GRIB_SUCCESS)
+            return ret;
+        if ((ret = grib_set_long_internal(h, "startStep", start.value<long>())) != GRIB_SUCCESS)
+            return ret;
+        if ((ret = grib_set_long_internal(h, "endStepUnit", end.unit().value<long>())) != GRIB_SUCCESS)
+            return ret;
+        if ((ret = grib_set_long_internal(h, "endStep", end.value<long>())) != GRIB_SUCCESS)
+            return ret;
+    }
+    catch (std::exception& e) {
+        std::string msg = std::string{"Failed to convert steps to: "} + std::to_string(*val) + " (" + e.what() + ")";
+        grib_context_log(a->context, GRIB_LOG_ERROR, "%s", msg.c_str());
+        return GRIB_INTERNAL_ERROR;
     }
 
     return GRIB_SUCCESS;
diff --git a/tests/grib_sub_hourly.sh b/tests/grib_sub_hourly.sh
index 2f399da0f..bb7bac891 100755
--- a/tests/grib_sub_hourly.sh
+++ b/tests/grib_sub_hourly.sh
@@ -62,86 +62,109 @@ fi
 instantaneous_field=$data_dir/reduced_gaussian_surface.grib2
 accumulated_field=$data_dir/reduced_gaussian_sub_area.grib2
 
+
+# ECC-1813: Test that we can set the stepUnits without setting the step
+in="$instantaneous_field"
+low_level_keys="forecastTime,indicatorOfUnitOfTimeRange:s"
+${tools_dir}/grib_set -s stepUnits=m,step=60 $in $temp
+grib_check_key_equals $temp "-p $low_level_keys" "60 m"
+${tools_dir}/grib_set -s stepUnits=s $temp $temp2
+grib_check_key_equals $temp2 "-p $low_level_keys" "3600 s"
+${tools_dir}/grib_set -s stepUnits=m $temp $temp2
+grib_check_key_equals $temp2 "-p $low_level_keys" "60 m"
+${tools_dir}/grib_set -s stepUnits=h $temp $temp2
+grib_check_key_equals $temp2 "-p $low_level_keys" "1 h"
+
+in="$accumulated_field"
+low_level_keys="forecastTime,indicatorOfUnitOfTimeRange:s,lengthOfTimeRange,indicatorOfUnitForTimeRange:s"
+${tools_dir}/grib_set -s stepUnits=m,stepRange=60-180 $in $temp
+grib_check_key_equals $temp "-p $low_level_keys" "60 m 120 m"
+${tools_dir}/grib_set -s stepUnits=s $temp $temp2
+grib_check_key_equals $temp2 "-p $low_level_keys" "3600 s 7200 s"
+${tools_dir}/grib_set -s stepUnits=m $temp $temp2
+grib_check_key_equals $temp2 "-p $low_level_keys" "60 m 120 m"
+${tools_dir}/grib_set -s stepUnits=h $temp $temp2
+grib_check_key_equals $temp2 "-p $low_level_keys" "1 h 2 h"
+
 # Check the lowercase alias 'stepunits' for a variety of step types (instant, accum etc)
 ${tools_dir}/grib_get -p stepunits $data_dir/tigge_cf_ecmwf.grib2
 
 
 #### Make sure that step, stepRange, startStep, endStep produce the same result for instantaneous fields
-fn="$instantaneous_field"
+in="$instantaneous_field"
 low_level_keys="forecastTime,indicatorOfUnitOfTimeRange:s"
 keys_step="step,step:s,step:i,step:d,stepUnits:s"
 keys_step_range="stepRange,stepRange:s,stepRange:i,stepRange:d,stepUnits:s"
 keys_start_step="startStep,startStep:s,startStep:i,startStep:d,stepUnits:s"
 keys_end_step="endStep,endStep:s,endStep:i,endStep:d,stepUnits:s"
-${tools_dir}/grib_set -s forecastTime=0,indicatorOfUnitOfTimeRange=h $fn $temp
+${tools_dir}/grib_set -s forecastTime=0,indicatorOfUnitOfTimeRange=h $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "0 h"
-${tools_dir}/grib_set -s stepUnits=m,step=59 $fn $temp
+${tools_dir}/grib_set -s stepUnits=m,step=59 $in $temp
 grib_check_key_equals $temp "-p $keys_step" "59m 59m 59 59 m"
 grib_check_key_equals $temp "-p $keys_step_range" "59m 59m 59 59 m"
 grib_check_key_equals $temp "-p $keys_start_step" "59m 59m 59 59 m"
 grib_check_key_equals $temp "-p $keys_end_step" "59m 59m 59 59 m"
 
-${tools_dir}/grib_set -s forecastTime=0,indicatorOfUnitOfTimeRange=h $fn $temp
+${tools_dir}/grib_set -s forecastTime=0,indicatorOfUnitOfTimeRange=h $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "0 h"
-${tools_dir}/grib_set -s step=59m $fn $temp
+${tools_dir}/grib_set -s step=59m $in $temp
 grib_check_key_equals $temp "-p $keys_step" "59m 59m 59 59 m"
 grib_check_key_equals $temp "-p $keys_step_range" "59m 59m 59 59 m"
 grib_check_key_equals $temp "-p $keys_start_step" "59m 59m 59 59 m"
 grib_check_key_equals $temp "-p $keys_end_step" "59m 59m 59 59 m"
 
-
 #### stepUnits overrides the units in the low level keys
 # if stepUnits=UNIT is set, then set the low level keys to UNIT
 # else optimise low level keys
 # instant fields:
 low_level_keys="forecastTime,indicatorOfUnitOfTimeRange:s,lengthOfTimeRange,indicatorOfUnitForTimeRange:s"
-fn="$instantaneous_field"
+in="$instantaneous_field"
 low_level_keys="forecastTime,indicatorOfUnitOfTimeRange:s"
 keys__="step,stepUnits:s"
 keys_s="step:s"
 keys_i="step:i,stepUnits:s"
 keys_d="step:d,stepUnits:s"
 
-${tools_dir}/grib_set -s stepUnits=m,step=60 $fn $temp
+${tools_dir}/grib_set -s stepUnits=m,step=60 $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "60 m"
 grib_check_key_equals $temp "-p $keys_s" "1$HOUR"
 grib_check_key_equals $temp "-p $keys_s -s stepUnits=m" "60m"
-${tools_dir}/grib_set -s stepUnits=m,step=60 $fn $temp
+${tools_dir}/grib_set -s stepUnits=m,step=60 $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "60 m"
 grib_check_key_equals $temp "-p $keys_s" "1$HOUR"
 grib_check_key_equals $temp "-p $keys_s -s stepUnits=m" "60m"
-${tools_dir}/grib_set -s step=60m $fn $temp
+${tools_dir}/grib_set -s step=60m $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "1 h"
 grib_check_key_equals $temp "-p $keys_s" "1$HOUR"
 grib_check_key_equals $temp "-p $keys_s -s stepUnits=m" "60m"
 
 
 # accumulated fields:
-fn="$accumulated_field"
+in="$accumulated_field"
 low_level_keys="forecastTime,indicatorOfUnitOfTimeRange:s,lengthOfTimeRange,indicatorOfUnitForTimeRange:s"
 keys__="step,startStep,endStep,stepRange,stepUnits:s"
 keys_s="step:s,startStep:s,endStep:s,stepRange:s,stepUnits:s"
 keys_i="step:i,startStep:i,endStep:i,stepRange:i,stepUnits:s"
 keys_d="step:d,startStep:d,endStep:d,stepRange:d,stepUnits:s"
 
-${tools_dir}/grib_set -s stepUnits=m,stepRange=60-120 $fn $temp
+${tools_dir}/grib_set -s stepUnits=m,stepRange=60-120 $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "60 m 60 m"
 grib_check_key_equals $temp "-p $keys_s" "2$HOUR 1$HOUR 2$HOUR 1$HOUR-2$HOUR h"
 grib_check_key_equals $temp "-p $keys_s -s stepUnits=m" "120m 60m 120m 60m-120m m"
-${tools_dir}/grib_set -s stepUnits=m,stepRange=60-120 $fn $temp
+${tools_dir}/grib_set -s stepUnits=m,stepRange=60-120 $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "60 m 60 m"
 grib_check_key_equals $temp "-p $keys_s" "2$HOUR 1$HOUR 2$HOUR 1$HOUR-2$HOUR h"
 grib_check_key_equals $temp "-p $keys_s -s stepUnits=m" "120m 60m 120m 60m-120m m"
-${tools_dir}/grib_set -s stepRange=60m-120m $fn $temp
+${tools_dir}/grib_set -s stepRange=60m-120m $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "1 h 1 h"
 grib_check_key_equals $temp "-p $keys_s" "2$HOUR 1$HOUR 2$HOUR 1$HOUR-2$HOUR h"
 grib_check_key_equals $temp "-p $keys_s -s stepUnits=m" "120m 60m 120m 60m-120m m"
 
 
 #### CHECK units
-fn="$accumulated_field"
+in="$accumulated_field"
 low_level_keys="forecastTime,indicatorOfUnitOfTimeRange:s,lengthOfTimeRange,indicatorOfUnitForTimeRange:s"
-${tools_dir}/grib_set -s forecastTime=0,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=96,indicatorOfUnitForTimeRange=h $fn $temp
+${tools_dir}/grib_set -s forecastTime=0,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=96,indicatorOfUnitForTimeRange=h $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "0 h 96 h"
 
 grib_check_key_equals $temp " -w count=1 -s stepUnits=s -p step:i,stepUnits:s" "345600 s"
@@ -162,38 +185,38 @@ grib_check_key_equals $temp " -w count=1 -s stepUnits=6h -p step,stepUnits:s" "1
 grib_check_key_equals $temp " -w count=1 -s stepUnits=12h -p step,stepUnits:s" "8x12h 12h"
 grib_check_key_equals $temp " -w count=1 -s stepUnits=D -p step,stepUnits:s" "4D D"
 
-${tools_dir}/grib_set -s stepUnits=s,startStep=0,endStep=345600  $fn $temp
+${tools_dir}/grib_set -s stepUnits=s,startStep=0,endStep=345600  $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "0 s 345600 s"
-${tools_dir}/grib_set -s stepUnits=m,startStep=0,endStep=5760  $fn $temp
+${tools_dir}/grib_set -s stepUnits=m,startStep=0,endStep=5760  $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "0 m 5760 m"
-${tools_dir}/grib_set -s stepUnits=h,startStep=0,endStep=96  $fn $temp
+${tools_dir}/grib_set -s stepUnits=h,startStep=0,endStep=96  $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "0 h 96 h"
-${tools_dir}/grib_set -s stepUnits=6h,startStep=0,endStep=16  $fn $temp
+${tools_dir}/grib_set -s stepUnits=6h,startStep=0,endStep=16  $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "0 6h 16 6h"
-${tools_dir}/grib_set -s stepUnits=12h,startStep=0,endStep=8  $fn $temp
+${tools_dir}/grib_set -s stepUnits=12h,startStep=0,endStep=8  $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "0 12h 8 12h"
-${tools_dir}/grib_set -s stepUnits=D,startStep=0,endStep=4  $fn $temp
+${tools_dir}/grib_set -s stepUnits=D,startStep=0,endStep=4  $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "0 D 4 D"
 
 
 #### CHECK negative forecastTime
-fn="$accumulated_field"
+in="$accumulated_field"
 low_level_keys="forecastTime,indicatorOfUnitOfTimeRange:s,lengthOfTimeRange,indicatorOfUnitForTimeRange:s"
-${tools_dir}/grib_set -s forecastTime=-6,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=6,indicatorOfUnitForTimeRange=h $fn $temp
+${tools_dir}/grib_set -s forecastTime=-6,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=6,indicatorOfUnitForTimeRange=h $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "-6 h 6 h"
 
 grib_check_key_equals $temp "-s stepUnits:s=h -p startStep:s,endStep:s" "-6$HOUR 0$HOUR"
 grib_check_key_equals $temp "-s stepUnits:s=m -p startStep:s,endStep:s" "-360m 0m"
 grib_check_key_equals $temp "-s stepUnits:s=s -p startStep:s,endStep:s" "-21600s 0s"
 
-${tools_dir}/grib_set -s forecastTime=-48,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=0,indicatorOfUnitForTimeRange=h $fn $temp
+${tools_dir}/grib_set -s forecastTime=-48,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=0,indicatorOfUnitForTimeRange=h $in $temp
 grib_check_key_equals $temp "-p stepRange" "-48$HOUR"
 
 
 #### CHECK: check optimal units are set correctly in GRIB files
-fn="$accumulated_field"
+in="$accumulated_field"
 low_level_keys="forecastTime,indicatorOfUnitOfTimeRange:s,lengthOfTimeRange,indicatorOfUnitForTimeRange:s"
-${tools_dir}/grib_set -s forecastTime=24,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=1,indicatorOfUnitForTimeRange=D $fn $temp
+${tools_dir}/grib_set -s forecastTime=24,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=1,indicatorOfUnitForTimeRange=D $in $temp
 grib_check_key_equals $temp    "-p $low_level_keys" "24 h 1 D"
 
 ### TODO(maee): @Shahram: how to make parameters position independent
@@ -220,18 +243,18 @@ grib_check_key_equals $temp2   "-p $low_level_keys" "60 h 120 h"
 ${tools_dir}/grib_set -s stepUnits:s=h,startStep:i=60,endStep:i=180 $temp $temp2
 grib_check_key_equals $temp2   "-p $low_level_keys" "60 h 120 h"
 
-#fn="$accumulated_field"
+#in="$accumulated_field"
 #low_level_keys="forecastTime,indicatorOfUnitOfTimeRange:s,lengthOfTimeRange,indicatorOfUnitForTimeRange:s"
 ##high_level_keys="startStep:s,endStep:s"
 #high_level_keys="startStep:i,endStep:i"
-#${tools_dir}/grib_set -s forecastTime=24,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=1,indicatorOfUnitForTimeRange=D $fn $temp
+#${tools_dir}/grib_set -s forecastTime=24,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=1,indicatorOfUnitForTimeRange=D $in $temp
 #grib_check_key_equals $temp    "-p $low_level_keys" "24 h 1 D"
 #grib_check_key_equals $temp   "-p $high_level_keys" "24 48"
 #${tools_dir}/grib_set -s startStep:i=24 $temp $temp2
 #grib_check_key_equals $temp2   "-p $low_level_keys" "24 h 0 h"
 #grib_check_key_equals $temp2   "-p $high_level_keys" "24 24"
 
-#${tools_dir}/grib_set -s forecastTime=24,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=24,indicatorOfUnitForTimeRange=h $fn $temp
+#${tools_dir}/grib_set -s forecastTime=24,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=24,indicatorOfUnitForTimeRange=h $in $temp
 #grib_check_key_equals $temp    "-p $low_level_keys" "24 h 24 h"
 #grib_check_key_equals $temp   "-p $high_level_keys" "24 48"
 #${tools_dir}/grib_set -s startStep:i=24 $temp $temp2
@@ -240,9 +263,9 @@ grib_check_key_equals $temp2   "-p $low_level_keys" "60 h 120 h"
 #exit
 
 #### CHECK: grib_set - endStep + stepUnits
-fn="$accumulated_field"
+in="$accumulated_field"
 low_level_keys="forecastTime,indicatorOfUnitOfTimeRange:s,lengthOfTimeRange,indicatorOfUnitForTimeRange:s"
-${tools_dir}/grib_set -s forecastTime=24,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=1,indicatorOfUnitForTimeRange=D $fn $temp
+${tools_dir}/grib_set -s forecastTime=24,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=1,indicatorOfUnitForTimeRange=D $in $temp
 grib_check_key_equals $temp    "-p $low_level_keys" "24 h 1 D"
 
 # Use range unit: hour
@@ -302,14 +325,14 @@ ${tools_dir}/grib_set -s stepRange:s=62D-122D $temp $temp2
 grib_check_key_equals $temp2   "-p $low_level_keys" "1488 h 1440 h"
 grib_check_key_equals $temp2   "-p stepRange:s"     "1488$HOUR-2928$HOUR"
 
-fn="$instantaneous_field"
+in="$instantaneous_field"
 low_level_keys="forecastTime,indicatorOfUnitOfTimeRange:s"
 keys__="step,stepUnits:s"
 keys_s="step:s"
 keys_i="step:i,stepUnits:s"
 keys_d="step:d,stepUnits:s"
 
-${tools_dir}/grib_set -s forecastTime=59,indicatorOfUnitOfTimeRange=m $fn $temp
+${tools_dir}/grib_set -s forecastTime=59,indicatorOfUnitOfTimeRange=m $in $temp
 grib_check_key_equals $temp "-p $keys__ -s stepUnits=s" "3540s s"
 grib_check_key_equals $temp "-p $keys__ -s stepUnits=m" "59m m"
 #grib_check_key_equals $temp "-p $keys__ -s stepUnits=h" "0" # not supported
@@ -324,7 +347,7 @@ grib_check_key_equals $temp "-p $keys_d -s stepUnits=m" "59 m"
 #grib_check_key_equals $temp "-p $keys_d -s stepUnits=h" "0.983333" # not supported
 
 
-${tools_dir}/grib_set -s forecastTime=0,indicatorOfUnitOfTimeRange=m $fn $temp
+${tools_dir}/grib_set -s forecastTime=0,indicatorOfUnitOfTimeRange=m $in $temp
 grib_check_key_equals $temp "-p $keys_i -s stepUnits=s" "0 s"
 grib_check_key_equals $temp "-p $keys_i -s stepUnits=m" "0 m"
 grib_check_key_equals $temp "-p $keys_i -s stepUnits=h" "0 h"
@@ -333,14 +356,14 @@ grib_check_key_equals $temp "-p $keys_d -s stepUnits=m" "0 m"
 grib_check_key_equals $temp "-p $keys_d -s stepUnits=h" "0 h"
 
 
-fn="$instantaneous_field"
+in="$instantaneous_field"
 low_level_keys="forecastTime,indicatorOfUnitOfTimeRange:s"
 keys__="step,stepUnits:s"
 keys_s="step:s,stepUnits:s"
 keys_i="step:i,stepUnits:s"
 keys_d="step:d,stepUnits:s"
 
-${tools_dir}/grib_set -s forecastTime=0,indicatorOfUnitOfTimeRange=m $fn $temp
+${tools_dir}/grib_set -s forecastTime=0,indicatorOfUnitOfTimeRange=m $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "0 m"
 grib_check_key_equals $temp "-p $keys__" "0m m"
 grib_check_key_equals $temp "-p $keys_s" "0m m"
@@ -361,7 +384,7 @@ grib_check_key_equals $temp "-p $keys_d -s stepUnits=m" "0 m"
 grib_check_key_equals $temp "-p $keys_d -s stepUnits=h" "0 h"
 
 
-${tools_dir}/grib_set -s forecastTime=59,indicatorOfUnitOfTimeRange=m $fn $temp
+${tools_dir}/grib_set -s forecastTime=59,indicatorOfUnitOfTimeRange=m $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "59 m"
 grib_check_key_equals $temp "-p $keys__" "59m m"
 #grib_check_key_equals $temp    "-p $keys_s" "59"
@@ -369,14 +392,14 @@ grib_check_key_equals $temp "-p $keys_s" "59m m"
 grib_check_key_equals $temp "-p $keys_i" "59 m"
 grib_check_key_equals $temp "-p $keys_d" "59 m"
 
-${tools_dir}/grib_set -s forecastTime=60,indicatorOfUnitOfTimeRange=m $fn $temp
+${tools_dir}/grib_set -s forecastTime=60,indicatorOfUnitOfTimeRange=m $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "60 m"
 grib_check_key_equals $temp "-p $keys__" "1$HOUR h"
 grib_check_key_equals $temp "-p $keys_s" "1$HOUR h"
 grib_check_key_equals $temp "-p $keys_i" "1 h"
 grib_check_key_equals $temp "-p $keys_d" "1 h"
 
-${tools_dir}/grib_set -s forecastTime=61,indicatorOfUnitOfTimeRange=m $fn $temp
+${tools_dir}/grib_set -s forecastTime=61,indicatorOfUnitOfTimeRange=m $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "61 m"
 grib_check_key_equals $temp "-p $keys__" "61m m"
 #grib_check_key_equals $temp    "-p $keys_s" "61"
@@ -384,14 +407,14 @@ grib_check_key_equals $temp "-p $keys_s" "61m m"
 grib_check_key_equals $temp "-p $keys_i" "61 m"
 grib_check_key_equals $temp "-p $keys_d" "61 m"
 
-${tools_dir}/grib_set -s forecastTime=24,indicatorOfUnitOfTimeRange=h $fn $temp
+${tools_dir}/grib_set -s forecastTime=24,indicatorOfUnitOfTimeRange=h $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "24 h"
 grib_check_key_equals $temp "-p $keys__" "24$HOUR h"
 grib_check_key_equals $temp "-p $keys_s" "24$HOUR h"
 grib_check_key_equals $temp "-p $keys_i" "24 h"
 grib_check_key_equals $temp "-p $keys_d" "24 h"
 
-${tools_dir}/grib_set -s forecastTime=1440,indicatorOfUnitOfTimeRange=m $fn $temp
+${tools_dir}/grib_set -s forecastTime=1440,indicatorOfUnitOfTimeRange=m $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "1440 m"
 grib_check_key_equals $temp "-p $keys__" "24$HOUR h"
 grib_check_key_equals $temp "-p $keys_s" "24$HOUR h"
@@ -399,40 +422,40 @@ grib_check_key_equals $temp "-p $keys_i" "24 h"
 grib_check_key_equals $temp "-p $keys_d" "24 h"
 
 
-fn="$accumulated_field"
+in="$accumulated_field"
 low_level_keys="forecastTime,indicatorOfUnitOfTimeRange:s,lengthOfTimeRange,indicatorOfUnitForTimeRange:s"
-${tools_dir}/grib_set -s stepRange=60m-2h $fn $temp
+${tools_dir}/grib_set -s stepRange=60m-2h $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "1 h 1 h"
 
-fn="$accumulated_field"
+in="$accumulated_field"
 low_level_keys="forecastTime,indicatorOfUnitOfTimeRange:s,lengthOfTimeRange,indicatorOfUnitForTimeRange:s"
 keys__="stepRange,startStep,endStep"
 keys_s="stepRange:s,startStep:s,endStep:s"
 keys_i="stepRange:i,startStep:i,endStep:i"
 keys_d="stepRange:d,startStep:d,endStep:d"
 
-${tools_dir}/grib_set -s forecastTime=0,indicatorOfUnitOfTimeRange=m,lengthOfTimeRange=2,indicatorOfUnitForTimeRange=h $fn $temp
+${tools_dir}/grib_set -s forecastTime=0,indicatorOfUnitOfTimeRange=m,lengthOfTimeRange=2,indicatorOfUnitForTimeRange=h $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "0 m 2 h"
 grib_check_key_equals $temp "-p $keys__" "0$HOUR-2$HOUR 0$HOUR 2$HOUR"
 grib_check_key_equals $temp "-p $keys_s" "0$HOUR-2$HOUR 0$HOUR 2$HOUR"
 grib_check_key_equals $temp "-p $keys_i" "2 0 2"
 grib_check_key_equals $temp "-p $keys_d" "2 0 2"
 
-${tools_dir}/grib_set -s forecastTime=24,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=1,indicatorOfUnitForTimeRange=D $fn $temp
+${tools_dir}/grib_set -s forecastTime=24,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=1,indicatorOfUnitForTimeRange=D $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "24 h 1 D"
 grib_check_key_equals $temp "-p $keys__" "24$HOUR-48$HOUR 24$HOUR 48$HOUR"
 grib_check_key_equals $temp "-p $keys_s" "24$HOUR-48$HOUR 24$HOUR 48$HOUR"
 grib_check_key_equals $temp "-p $keys_i" "48 24 48" 
 grib_check_key_equals $temp "-p $keys_d" "48 24 48" 
 
-${tools_dir}/grib_set -s forecastTime=25,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=1,indicatorOfUnitForTimeRange=D $fn $temp
+${tools_dir}/grib_set -s forecastTime=25,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=1,indicatorOfUnitForTimeRange=D $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "25 h 1 D"
 grib_check_key_equals $temp "-p $keys__" "25$HOUR-49$HOUR 25$HOUR 49$HOUR"
 grib_check_key_equals $temp "-p $keys_s" "25$HOUR-49$HOUR 25$HOUR 49$HOUR"
 grib_check_key_equals $temp "-p $keys_i" "49 25 49" 
 grib_check_key_equals $temp "-p $keys_d" "49 25 49" 
 
-${tools_dir}/grib_set -s forecastTime=45,indicatorOfUnitOfTimeRange=m,lengthOfTimeRange=15,indicatorOfUnitForTimeRange=m $fn $temp
+${tools_dir}/grib_set -s forecastTime=45,indicatorOfUnitOfTimeRange=m,lengthOfTimeRange=15,indicatorOfUnitForTimeRange=m $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "45 m 15 m"
 grib_check_key_equals $temp "-p $keys__" "45m-60m 45m 60m" 
 #grib_check_key_equals $temp    "-p $keys_s" "45-60 45 60"  
@@ -440,28 +463,28 @@ grib_check_key_equals $temp "-p $keys_s" "45m-60m 45m 60m"
 grib_check_key_equals $temp "-p $keys_i" "60 45 60"  
 grib_check_key_equals $temp "-p $keys_d" "60 45 60"
 
-${tools_dir}/grib_set -s forecastTime=60,indicatorOfUnitOfTimeRange=m,lengthOfTimeRange=2,indicatorOfUnitForTimeRange=h $fn $temp
+${tools_dir}/grib_set -s forecastTime=60,indicatorOfUnitOfTimeRange=m,lengthOfTimeRange=2,indicatorOfUnitForTimeRange=h $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "60 m 2 h"
 grib_check_key_equals $temp "-p $keys__" "1$HOUR-3$HOUR 1$HOUR 3$HOUR" 
 grib_check_key_equals $temp "-p $keys_s" "1$HOUR-3$HOUR 1$HOUR 3$HOUR"
 grib_check_key_equals $temp "-p $keys_i" "3 1 3"
 grib_check_key_equals $temp "-p $keys_d" "3 1 3"
 
-${tools_dir}/grib_set -s forecastTime=18,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=6,indicatorOfUnitForTimeRange=h $fn $temp
+${tools_dir}/grib_set -s forecastTime=18,indicatorOfUnitOfTimeRange=h,lengthOfTimeRange=6,indicatorOfUnitForTimeRange=h $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "18 h 6 h"
 grib_check_key_equals $temp "-p $keys__" "18$HOUR-24$HOUR 18$HOUR 24$HOUR"
 grib_check_key_equals $temp "-p $keys_s" "18$HOUR-24$HOUR 18$HOUR 24$HOUR"
 grib_check_key_equals $temp "-p $keys_i" "24 18 24"
 grib_check_key_equals $temp "-p $keys_d" "24 18 24"
 
-${tools_dir}/grib_set -s forecastTime=1080,indicatorOfUnitOfTimeRange=m,lengthOfTimeRange=360,indicatorOfUnitForTimeRange=m $fn $temp
+${tools_dir}/grib_set -s forecastTime=1080,indicatorOfUnitOfTimeRange=m,lengthOfTimeRange=360,indicatorOfUnitForTimeRange=m $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "1080 m 360 m"
 grib_check_key_equals $temp "-p $keys__" "18$HOUR-24$HOUR 18$HOUR 24$HOUR"
 grib_check_key_equals $temp "-p $keys_s" "18$HOUR-24$HOUR 18$HOUR 24$HOUR"
 grib_check_key_equals $temp "-p $keys_i" "24 18 24"
 grib_check_key_equals $temp "-p $keys_d" "24 18 24"
 
-${tools_dir}/grib_set -s forecastTime=1080,indicatorOfUnitOfTimeRange=m,lengthOfTimeRange=6,indicatorOfUnitForTimeRange=h $fn $temp
+${tools_dir}/grib_set -s forecastTime=1080,indicatorOfUnitOfTimeRange=m,lengthOfTimeRange=6,indicatorOfUnitForTimeRange=h $in $temp
 grib_check_key_equals $temp "-p $low_level_keys" "1080 m 6 h"
 grib_check_key_equals $temp "-p $keys__" "18$HOUR-24$HOUR 18$HOUR 24$HOUR"
 grib_check_key_equals $temp "-p $keys_s" "18$HOUR-24$HOUR 18$HOUR 24$HOUR"