Add utc format to formula parser. Test date conversions to from utc.

src/formula.cc

@@ -227,7 +227,8 @@ double Token::val(const string &s)
     else if (type == TokenType::DATETIME)
     {
         struct tm time {};
-        strptime(v.c_str(), "'%Y-%m-%d %H:%M:%S'", &time);
+        char *ok = strptime(v.c_str(), "'%Y-%m-%d %H:%M:%S'", &time);
+        if (!ok) ok = strptime(v.c_str(), "'%Y-%m-%dT%H:%M:%SZ'", &time);
         time_t epoch = mktime(&time);
         double result = (double)epoch;
         return result;
@@ -320,7 +321,8 @@ size_t FormulaImplementation::findNumber(size_t i)
 size_t FormulaImplementation::findDateTime(size_t i)
 {
     // A datetime is converted into a unix timestamp.
-    // Patterns: '2222-22-22 11:11:00'
+    // Patterns: '2022-12-30T09:32:45Z'
+    //           '2222-22-22 11:11:00'
     //           '2222-22-22 11:11'
     //           '2222-22-22'
 
@@ -329,6 +331,12 @@ size_t FormulaImplementation::findDateTime(size_t i)
     const char *end;
 
     memset(&time, 0, sizeof(time));
+    if (i+21 < formula_.length())
+    {
+        end = strptime(start, "'%Y-%m-%dT%H:%M:%SZ'", &time);
+        if (distance(start, end) == 22) return 22;
+    }
+
     if (i+20 < formula_.length())
     {
         end = strptime(start, "'%Y-%m-%d %H:%M:%S'", &time);

src/meters.cc

@@ -860,7 +860,10 @@ string MeterCommonImplementation::datetimeOfUpdateRobot()
     char datetime[40];
     memset(datetime, 0, sizeof(datetime));
     // This is the date time in the Greenwich timezone (Zulu time), dont get surprised!
-    strftime(datetime, sizeof(datetime), "%FT%TZ", gmtime(&datetime_of_update_));
+    time_t d = datetime_of_update_;
+    struct tm ts;
+    gmtime_r(&d, &ts);
+    strftime(datetime, sizeof(datetime), "%FT%TZ", &ts);
     return string(datetime);
 }
 
@@ -1184,6 +1187,13 @@ bool checkPrintableField(string *buf, string desired_field_name, Meter *m, Teleg
                 *buf += c;
                 return true;
             }
+            else if (fi.displayUnit() == Unit::DateTimeUTC)
+            {
+                double d = m->getNumericValue(&fi, Unit::DateTimeUTC);
+                *buf += strTimestampUTC(d);
+                *buf += c;
+                return true;
+            }
             else
             {
                 // Default unit.
@@ -1767,6 +1777,10 @@ string FieldInfo::renderJson(Meter *m, DVEntry *dve)
         {
             s += "\""+field_name+"_"+display_unit_s+"\":\""+strdatetime(m->getNumericValue(field_name, Unit::DateTimeLT))+"\"";
         }
+        else if (displayUnit() == Unit::DateTimeUTC)
+        {
+            s += "\""+field_name+"_"+display_unit_s+"\":\""+strTimestampUTC(m->getNumericValue(field_name, Unit::DateTimeUTC))+"\"";
+        }
         else
         {
             // All numeric values.

src/util.cc

@@ -2405,3 +2405,14 @@ int strlen_utf8(const char *s)
     for (; *s; ++s) if ((*s & 0xC0) != 0x80) ++len;
     return len;
 }
+
+string strTimestampUTC(double v)
+{
+    char datetime[40];
+    memset(datetime, 0, sizeof(datetime));
+    time_t d = v;
+    struct tm ts;
+    gmtime_r(&d, &ts);
+    strftime(datetime, sizeof(datetime), "%FT%TZ", &ts);
+    return string(datetime);
+}

src/util.h

@@ -82,6 +82,8 @@ std::string strdatetime(double v);
 // Return for example: 2010-03-21 15:22:03
 std::string strdatetimesec(struct tm *date);
 std::string strdatetimesec(double v);
+// Return UTC timestamp:
+std::string strTimestampUTC(double v);
 void addMonths(struct tm* date, int m);
 double addMonths(double t, int m);
 

test.sh

@@ -93,6 +93,9 @@ if [ "$?" != "0" ]; then RC="1"; fi
 tests/test_formulas.sh $PROG
 if [ "$?" != "0" ]; then RC="1"; fi
 
+tests/test_calculate_dates.sh $PROG
+if [ "$?" != "0" ]; then RC="1"; fi
+
 tests/test_fields.sh $PROG
 if [ "$?" != "0" ]; then RC="1"; fi
 

tests/test_calculate_dates.sh

@@ -0,0 +1,103 @@
+#!/bin/sh
+
+PROG="$1"
+
+rm -rf testoutput
+mkdir -p testoutput
+TEST=testoutput
+
+TESTNAME="Test date calculations"
+TESTRESULT="ERROR"
+
+HEX="5E44A51139259471410D7A720050052F2F0C06742400008C1006000000000C13823522008C2013494400000B3B0000000C2B000000000A5A22030A5E91020AA61800004C0619130000CC100600000000426CDF252F2F2F2F2F2F2F2F2F2F2F"
+
+cat > $TEST/test_expected.txt <<EOF
+    "set_date":"2022-05-31",
+    "set_1_fromd_utc":"2022-12-22T01:00:00Z",
+    "set_2_fromdhm_utc":"2022-12-22T13:12:00Z",
+    "set_3_fromdhms_utc":"2022-12-22T13:12:12Z",
+    "set_4_fromdhmsz_utc":"2022-12-22T13:12:12Z",
+    "set_5_fromdut_utc":"2022-12-22T12:12:12Z",
+    "set_6_from_setdate_utc":"2022-05-31T01:00:00Z",
+    "set_7_fromd_datetime":"2022-12-22 00:00",
+    "set_8_fromdhm_datetime":"2022-12-22 12:12",
+    "set_9_fromdhms_datetime":"2022-12-22 12:12",
+    "set_10_fromdhmsz_datetime":"2022-12-22 12:12",
+    "set_11_fromdhmsz_datetime":"2022-12-22 11:12",
+    "set_12_from_setdate_datetime":"2022-05-31 00:00",
+    "set_13_fromd_date":"2022-12-22",
+    "set_14_fromdhm_date":"2022-12-22",
+    "set_15_fromdhms_date":"2022-12-22",
+    "set_16_fromdhmsz_date":"2022-12-22",
+    "set_17_fromdhmsz_date":"2022-12-22",
+    "set_18_from_setdate_date":"2022-05-31",
+    "set_19_fromd_ut":1671670800,
+    "set_20_fromdhm_ut":1671714720,
+    "set_21_fromdhms_ut":1671714732,
+    "set_22_fromdhmsz_ut":1671714732,
+    "set_23_fromdhmsz_ut":1671711132,
+    "set_24_from_setdate_ut":1653958800,
+    "set_25_fromd_datetime":"2023-01-22 00:00",
+    "set_26_fromdhm_datetime":"2023-01-22 12:12",
+    "set_27_fromdhms_datetime":"2023-01-22 12:12",
+    "set_28_fromdhmsz_datetime":"2023-01-22 12:12",
+    "set_29_fromdhmsz_datetime":"2023-01-22 11:12",
+    "set_30_from_setdate_datetime":"2022-06-30 00:00",
+EOF
+
+# TZ=UTC+1 date --date 2022-12-22T12:12:12Z +%s  --> 1671711132 # UTC time
+# TZ=UTC+1 date --date '2022-12-22 12:12:12' +%s --> 1671714732 # Local time in UTC+1 ie Stockholm no daylight savings.
+# TZ=UTC+1 date --date '2022-12-22 12:12' +%s    --> 1671714720
+# TZ=UTC+1 date --date '2022-12-22' +%s          --> 1671670800
+
+# Test using a fixed timezone without daylight savings
+# This is necessary to have the utc conversion be stable for testing.
+TZ=UTC+1 $PROG --format=json --ppjson \
+  --calculate_set_1_fromd_utc="'2022-12-22'" \
+  --calculate_set_2_fromdhm_utc="'2022-12-22 12:12'" \
+  --calculate_set_3_fromdhms_utc="'2022-12-22 12:12:12'" \
+  --calculate_set_4_fromdhmsz_utc="'2022-12-22T12:12:12Z'" \
+  --calculate_set_5_fromdut_utc='1671711132 ut' \
+  --calculate_set_6_from_setdate_utc=set_date \
+  \
+  --calculate_set_7_fromd_datetime="'2022-12-22'" \
+  --calculate_set_8_fromdhm_datetime="'2022-12-22 12:12'" \
+  --calculate_set_9_fromdhms_datetime="'2022-12-22 12:12:12'" \
+  --calculate_set_10_fromdhmsz_datetime="'2022-12-22T12:12:12Z'" \
+  --calculate_set_11_fromdhmsz_datetime='1671711132 ut'\
+  --calculate_set_12_from_setdate_datetime=set_date \
+  \
+  --calculate_set_13_fromd_date="'2022-12-22'" \
+  --calculate_set_14_fromdhm_date="'2022-12-22 12:12'" \
+  --calculate_set_15_fromdhms_date="'2022-12-22 12:12:12'" \
+  --calculate_set_16_fromdhmsz_date="'2022-12-22T12:12:12Z'" \
+  --calculate_set_17_fromdhmsz_date='1671711132 ut'\
+  --calculate_set_18_from_setdate_date=set_date \
+  \
+  --calculate_set_19_fromd_ut="'2022-12-22'" \
+  --calculate_set_20_fromdhm_ut="'2022-12-22 12:12'" \
+  --calculate_set_21_fromdhms_ut="'2022-12-22 12:12:12'" \
+  --calculate_set_22_fromdhmsz_ut="'2022-12-22T12:12:12Z'" \
+  --calculate_set_23_fromdhmsz_ut='1671711132 ut'\
+  --calculate_set_24_from_setdate_ut=set_date \
+  \
+  --calculate_set_25_fromd_datetime="'2022-12-22' + 1 month" \
+  --calculate_set_26_fromdhm_datetime="'2022-12-22 12:12' + 1 month" \
+  --calculate_set_27_fromdhms_datetime="'2022-12-22 12:12:12' + 1 month" \
+  --calculate_set_28_fromdhmsz_datetime="'2022-12-22T12:12:12Z' + 1 month" \
+  --calculate_set_29_fromdhmsz_datetime='1671711132 ut + 1 month'\
+  --calculate_set_30_from_setdate_datetime='set_date + 1 month'\
+      "$HEX" \
+      GURKA sharky774 71942539 NOKEY | grep \"set_ > $TEST/test_output.txt
+
+if [ "$?" = "0" ]
+then
+    diff $TEST/test_expected.txt $TEST/test_output.txt
+    if [ "$?" = "0" ]
+    then
+        echo "OK: $TESTNAME"
+        TESTRESULT="OK"
+    fi
+fi
+
+if [ "$TESTRESULT" = "ERROR" ]; then echo ERROR: $TESTNAME;  exit 1; fi