Update JSON output.

man/remind.1.in

@@ -693,6 +693,7 @@ Its syntax is:
 [\fBSCANFROM\fR \fIscan_date\fR | \fBFROM\fR \fIstart_date\fR]
 [\fBDURATION\fR \fIduration\fR]
 [\fBTAG\fR \fItag\fR]
+[\fBTZ\fR \fItimezone\fR]
 [\fBINFO\fR "\fIinfo_string\fR"]
 \fBMSG\fR | \fBMSF\fR | \fBRUN\fR | \fBCAL\fR | \fBSATISFY\fR |
 \fBSPECIAL\fR \fIspecial\fR | \fBPS\fR | \fBPSFILE\fR
@@ -2042,6 +2043,55 @@ In Purge Mode, \fBRemind\fR will not purge TODOs unless they have been marked
 as complete.  In the case of a recurring TODO, \fBRemind\fR will not purge
 it until the last occurrence is marked as complete.
 .PP
+.SH TIMEZONE SUPPORT
+.PP
+The \fBREM\fR command supports an optional \fBTZ\fR keyword, which should
+be followed by the \fIcase-sensitive\fR time zone name in which the
+command is to be interpreted.  Note that if you use the \fBTZ\fR keyword,
+then you \fImust also\fR use an \fBAT\fR clause.  Here are some examples:
+.PP
+.nf
+    REM Wednesday AT 14:00 TZ America/Toronto MSG 2PM Eastern (%2).
+    REM Wednesday AT 23:59 TZ America/Los_Angeles SATISFY [$Td == 13] MSG Foo %b %2.
+.fi
+.PP
+Within a \fBSATISFY\fR clause, all trigger functions are interpreted in
+the time zone specified in the \fBREM\fR command.  Outside the \fBREM\fR
+command, however, trigger functions are adjusted to the local time
+zone.  If the local time zone is UTC and we feed \fBRemind\fR the
+following file on 2025-09-04 UTC:
+.PP
+.nf
+    SET $AddBlankLines 0
+    BANNER %
+    REM Wednesday AT 14:00 TZ America/Toronto MSG 2PM Eastern (%2).
+    set a $T
+    set b $Tt
+    REM MSG a = [a], b = [b]
+    REM Wednesday AT 23:59 TZ America/Los_Angeles SATISFY [$Td == 13] MSG Foo %b %2.
+    set c $T
+    set d $Tt
+    REM MSG c = [c], d = [d]
+.fi
+.PP
+Then the output is as follows:
+.PP
+.nf
+    a = 2025-09-10, b = 18:00
+    c = 2026-05-14, d = 06:59
+.fi
+.PP
+That is because the trigger date of the first (Wednesday, 2025-09-10
+at 14:00 Eastern time) is 2025-09-10 at 18:00 UTC.  In the second case,
+Wednesday, 13 May 2026 is the SATISFied trigger date, which is
+adjusted to Thursday, 14 May 2026 at 06:59 UTC because of the
+time zone adjustment.
+.PP
+If you use an invalid time zone name after the \fBTZ\fR keyword,
+results are undefined.  Unfortunately, \fBRemind\fR cannot diagnose
+this error becase the C library \fBtzset()\fR function has no
+error return.
+.PP
 .SH THE OMIT COMMAND
 .PP
 In addition to being a keyword in the \fBREM\fR command,

src/calendar.c

@@ -2316,6 +2316,9 @@ static int DoCalRem(ParsePtr p, int col)
         e->nonconst_expr = nonconst_expr;
         e->if_depth = get_if_pointer() - get_base_if_pointer();
         e->trig = trig;
+        if (e->trig.tz) {
+            e->trig.tz = StrDup(e->trig.tz);
+        }
         e->tt = tim;
 #ifdef REM_USE_WCHAR
         e->wc_pos = NULL;
@@ -2412,6 +2415,9 @@ static void WriteSimpleEntryProtocol1(CalEntry const *e)
 void WriteJSONTimeTrigger(TimeTrig const *tt)
 {
     PrintJSONKeyPairTime("time", tt->ttime);
+    if (tt->ttime != tt->ttime_orig) {
+        PrintJSONKeyPairTime("time_in_tz", tt->ttime_orig);
+    }
     PrintJSONKeyPairTime("nexttime", tt->nexttime);
     PrintJSONKeyPairInt("tdelta", tt->delta);
     PrintJSONKeyPairInt("trep", tt->rep);
@@ -2543,6 +2549,10 @@ void WriteJSONTrigger(Trigger const *t, int include_tags)
     PrintJSONKeyPairDate("from", t->from);
     PrintJSONKeyPairInt("priority", t->priority);
     PrintJSONKeyPairDateTime("eventstart", t->eventstart);
+    if (t->eventstart_orig != NO_TIME &&
+        t->eventstart_orig != t->eventstart) {
+        PrintJSONKeyPairDateTime("eventstart_in_tz", t->eventstart_orig);
+    }
     if (t->eventduration != NO_TIME) {
         PrintJSONKeyPairInt("eventduration", t->eventduration);
     }
@@ -2564,6 +2574,7 @@ void WriteJSONTrigger(Trigger const *t, int include_tags)
         }
         PrintJSONKeyPairString("tags", DBufValue(&(t->tags)));
     }
+    PrintJSONKeyPairString("tz", t->tz);
 }
 
 static void WriteSimpleEntryProtocol2(CalEntry *e)

src/dorem.c

@@ -35,7 +35,7 @@ static int ComputeTrigDuration(TimeTrig const *t);
 
 static int CalledEnterTimezone = 0;
 
-int AdjustTriggerForTimeZone(Trigger const *trig, int dse, TimeTrig *tim)
+int AdjustTriggerForTimeZone(Trigger *trig, int dse, TimeTrig *tim)
 {
     int y, m, d, hour, minute;
     int r;
@@ -57,6 +57,8 @@ int AdjustTriggerForTimeZone(Trigger const *trig, int dse, TimeTrig *tim)
     dse = DSE(tm.tm_year+1900, tm.tm_mon, tm.tm_mday);
     tim->ttime = tm.tm_hour * 60 + tm.tm_min;
     SaveAllTriggerInfo(trig, tim, dse, tim->ttime, 1);
+    /* Adjust eventstart also */
+    trig->eventstart = dse * MINUTES_PER_DAY + tim->ttime;
     if (DebugFlag & DB_PRTTRIG) {
         fprintf(ErrFp, "%s(%s): Trig(tz_adj %s) = %s, %d %s, %d AT %02d:%02d",
                 GetCurrentFilename(), line_range(LineNoStart, LineNo), trig->tz,
@@ -612,6 +614,9 @@ int DoRem(ParsePtr p)
             }
             if (tim.ttime != NO_TIME) {
                 PrintJSONKeyPairInt("time", tim.ttime);
+                if (tim.ttime_orig != tim.ttime) {
+                    PrintJSONKeyPairInt("time_in_tz", tim.ttime_orig);
+                }
             }
             if (p->nonconst_expr) {
                 PrintJSONKeyPairInt("nonconst_expr", 1);
@@ -797,6 +802,7 @@ int ParseRem(ParsePtr s, Trigger *trig, TimeTrig *tim)
     trig->omitfunc[0] = 0;
     trig->duration_days = 0;
     trig->eventstart = NO_TIME;
+    trig->eventstart_orig = NO_TIME;
     trig->eventduration = NO_TIME;
     trig->maybe_uncomputable = 0;
     DBufInit(&(trig->tags));
@@ -1971,6 +1977,7 @@ int DoSatRemind(Trigger *trig, TimeTrig *tt, ParsePtr p)
         } else if (dse == start) {
             if (tt->ttime != NO_TIME) {
                 trig->eventstart = MINUTES_PER_DAY * r + tt->ttime;
+                trig->eventstart_orig = trig->eventstart;
                 if (tt->duration != NO_TIME) {
                     trig->eventduration = tt->duration;
                 }

src/protos.h

@@ -298,6 +298,6 @@ int system_to_stderr(char const *cmd);
 int system1(char const *cmd);
 int tz_set_tz (char const *tz);
 int tz_convert(int year, int month, int day, int hour, int minute, char const *src_tz, char const *tgt_tz, struct tm *tm);
-int AdjustTriggerForTimeZone(Trigger const *trig, int dse, TimeTrig *tim);
+int AdjustTriggerForTimeZone(Trigger *trig, int dse, TimeTrig *tim);
 void EnterTimezone(char const *tz);
 void ExitTimezone(char const *tz);

src/trigger.c

@@ -453,6 +453,7 @@ AdjustTriggerForDuration(int today, int r, Trigger *trig, TimeTrig *tim, int sav
     /* If we have an AT, save the original event start */
     if (tim->ttime != NO_TIME) {
         trig->eventstart = MINUTES_PER_DAY * r + tim->ttime;
+        trig->eventstart_orig = trig->eventstart;
         if (tim->duration != NO_TIME) {
             trig->eventduration = tim->duration;
         }
@@ -515,6 +516,7 @@ int ComputeTrigger(int today, Trigger *trig, TimeTrig *tim,
     if (r == today) {
         if (tim->ttime != NO_TIME) {
             trig->eventstart = MINUTES_PER_DAY * r + tim->ttime;
+            trig->eventstart_orig = trig->eventstart;
             if (tim->duration != NO_TIME) {
                 trig->eventduration = tim->duration;
             }

src/types.h

@@ -141,6 +141,7 @@ typedef struct {
     int priority;
     int duration_days;           /* Duration converted to days to search */
     int eventstart;              /* Original event start (datetime) */
+    int eventstart_orig;         /* Original event start in TZ (datetime) */
     int eventduration;           /* Original event duration (minutes) */
     int maybe_uncomputable;      /* Suppress "can't compute trigger" warnings */
     int addomit;                 /* Add trigger date to global OMITs */