Update WHATSNEW.

docs/WHATSNEW

@@ -1,5 +1,17 @@
 CHANGES TO REMIND
 
+* VERSION 4.2 Patch 3 - 2023-??-??
+
+- NEW FEATURE: Remind: add the orthodoxeaster() function to return the
+  date of Orthodox Easter.
+
+- IMPROVEMENT: Add Greek language support courtesy of JeiEl.
+
+- IMPROVEMENT: Add Greek holiday file courtesy of JeiEl.
+
+- BUG FIX: examples/defs.rem: Fix the calculation of US Tax Day as per
+  Tavis Ormandy and Tim Chase.
+
 * VERSION 4.2 Patch 2 - 2023-01-01
 
 - NEW FEATURE: Remind: Add the NOQUEUE modifier to the REM statement for

examples/defs.rem

@@ -157,7 +157,24 @@ REM Last Sunday in October ++2 UNTIL 1 Jan 2007 MSG Daylight Saving Time - %"DST
 REM First Sunday in November ++2 FROM 1 Jan 2007 MSG Daylight Saving Time - %"DST ends%" %b
 
 REM     Apr  1		MSG %"April Fool's%" Day
-REM Mon Tue Wed Thu Fri Sat 15 Apr MSG %"Income tax%" due
+
+# US Tax Day
+PUSH-OMIT-CONTEXT
+# Normal case: 16 April falls Mon-Fri
+REM 16 Apr SCANFROM -7 ADDOMIT SATISFY [$Tw >= 1 && $Tw <= 5] MSG Emancipation Day
+
+# 16 April falls on Saturday: Observe on the 15th
+REM 15 Apr SCANFROM -7 ADDOMIT SATISFY [$Tw == 5] MSG Emancipation Day (observed)
+
+# 16 April falls on Sunday: Observe on the 17th
+REM 17 Apr SCANFROM -7 ADDOMIT SATISFY [$Tw == 1] MSG Emancipation Day (observed)
+
+# If you live in Maine or Massachussetts, uncomment the next line
+# REM Third Monday in April SCANFROM -7 ADDOMIT MSG Patriots Day
+
+REM Apr 15 OMIT Sat Sun AFTER MSG Tax Day
+POP-OMIT-CONTEXT
+
 REM     May  5		MSG %"Cinco de Mayo%"
 REM First Sat in May 	MSG %"Kentucky Derby%"
 REM Second Sun in May	MSG %"Mother's Day%"

include/holidays/gr.rem

@@ -0,0 +1,39 @@
+# Greek national holidays
+# ΑΡΓΙΕΣ (για όλους)
+
+# fixed
+REM 1 Jan MSG ΠΡΩΤΟΧΡΟΝΙΑ
+REM 6 Jan MSG ΤΑ ΦΩΤΑ/ ΘΕΟΦΑΝΕΙΑ
+REM 25 Mar MSG η 25η Μαρτίου
+REM 15 Aug MSG 15Αύγουστος
+REM 28 Oct MSG ΟΧΙ
+REM 25 Dec MSG ΧΡΙΣΤΟΥΓΕΝΝΑ
+REM 26 Dec MSG ΧΡΙΣΤΟΥΓΕΝΝΑ2
+
+REM [orthodoxeaster($Uy)+1] ΔΕΥΤΕΡΑ ΤΟΥ ΠΑΣΧΑ
+
+
+# May first is a national holiday except if Sunday, day of great week (week before easter) or Monday after easter, then
+# minister decides moving that holiday. Here is a likely  assumption of how this day might be moved.
+# Uncomment following lines to enable.
+
+set PM date($Uy,5,1)
+# IF PM>=orthodoxeaster($Uy)-7 && PM<=orthodoxeaster($Uy)+1
+# IF PM<orthodoxeaster($Uy)-3
+# REM orthodoxeaster($Uy) -8 MSG πιθανόν ΕΡΓΑΤΙΚΗ Πρωτομαγιά
+# ELSE
+# REM [plusfunc(2)] MSG πιθανόν ΕΡΓΑΤΙΚΗ Πρωτομαγιά
+# ENDIF
+# ENDIF
+# REM [PM] OMIT Sun AFTER MSG Πρωτομαγιά
+
+REM 1 May MSG Πρωτομαγιά
+# end of May 1 speculations
+
+# The following are main national holidays per custom (observed by most but not all)
+REM [orthodoxeaster($Uy)] -48 MSG Καθαρά Δευτέρα
+REM [orthodoxeaster($Uy)] -2 MSG Μεγάλη Παρασκευή
+REM [orthodoxeaster($Uy)] -1 MSG Μεγάλο Σάββατο
+REM [orthodoxeaster($Uy)+50] MSG Αγίου Πνεύματος
+
+

include/lang/auto.rem

@@ -1,5 +1,9 @@
 # SPDX-License-Identifier: GPL-2.0-only
-SET autolang getenv("LC_ALL")
+SET autolang getenv("REMIND_LANG")
+
+IF autolang == ""
+    SET autolang getenv("LC_ALL")
+ENDIF
 IF autolang == ""
     SET autolang getenv("LANGUAGE")
 ENDIF

include/lang/gr.rem

@@ -0,0 +1,83 @@
+# Support for the Hellenic (Greek) language.
+# This file is part of REMIND.
+# REMIND is Copyright (C) 1992-2023 by Dianne Skoll
+# This file is derived from a translation by jarlaxl lamat (jarlaxl@freemail.gr)
+
+SET $Sunday "Κυριακή"
+SET $Monday "Δευτέρα"
+SET $Tuesday "Τρίτη"
+SET $Wednesday "Τετάρτη"
+SET $Thursday "Πέμπτη"
+SET $Friday "Παρασκευή"
+SET $Saturday "Σάββατο"
+
+SET $January "Ιανουάρ."
+SET $February "Φεβρουάρ."
+SET $March "Μάρτ."
+SET $April "Απρίλ."
+SET $May "Μαι."
+SET $June "Ιούν."
+SET $July "Ιούλ."
+SET $August "Αυγουστ."
+SET $September "Σεπτέμβρ."
+SET $October "Οκτώβρ."
+SET $November "Νοέμβρ."
+SET $December "Δεκέμβρ."
+
+SET $Today "σήμερα"
+SET $Tomorrow "αύριο"
+
+BANNER Υπενθυμίσεις: %w, %d %m, %y%o:
+
+SET $Am "πμ"
+SET $Pm "μμ"
+
+SET $Ago "πριν"
+SET $Fromnow "από τώρα"
+
+SET $On "την"
+
+SET $Now "τώρα"
+SET $At "στις"
+SET $Minute "λεπτά"
+SET $Hour "ώρες"
+SET $Is "είναι"
+SET $Was "ήταν"
+SET $And "και"
+SET $Hplu ""
+SET $Mplu ""
+
+FSET subst_bx(a, d, t) "σε " + (d - today()) + " ημέρες"
+FSET subst_ordinal(d)   "."
+FSET subst_a_alt(d)     wkday(d) + ", " + day(d) + ". " + mon(d) + " " + year(d)
+FSET subst_ax(alt, d, t) iif(alt, subst_a_alt(d), $On + " " + subst_a_alt(d))
+FSET subst_g_alt(d)     wkday(d) + ", " + day(d) + ". " + mon(d)
+FSET subst_gx(alt, d, t) iif(alt, subst_g_alt(d), $On + " " + subst_g_alt(d))
+FSET subst_ux(alt, d, t) subst_ax(alt, d, t)
+FSET subst_vx(alt, d, t) subst_gx(alt, d, t)
+
+# Localization of various astronomical events
+
+# Perihelion
+SET earthseasons_Perihelion_str  "Περιήλιον"
+
+# Vernal equinox
+SET earthseasons_EquinoxMar_str  "Εαρινή ισημερία"
+
+# Summer solstice
+SET earthseasons_SolsticeJun_str "Θερινό ηλιοστάσιο"
+
+# Aphelion
+SET earthseasons_Aphelion_str    "Αφήλιον"
+
+# Autumnal Equinox
+SET earthseasons_EquinoxSep_str  "Φθινοπωρινή ισημερία"
+
+# Winter Solstice
+SET earthseasons_SolsticeDec_str "Χειμερινό ηλιοστάσιο"
+
+# Daylight saving time starts
+SET daylightST_starts_str        "Έναρξη θέρους"
+
+# Daylight saving time ends
+SET daylightST_ends_str          "Τέλος θέρους"

man/remind.1.in

@@ -2939,6 +2939,11 @@ If \fIarg\fR is an \fBINT\fR, then returns the date of Easter Sunday
 for the specified year.  If \fIarg\fR is a \fBDATE\fR or
 \fBDATETIME\fR, then returns the date of the next Easter Sunday on or
 after \fIarg\fR.  (The time component of a datetime is ignored.)
+.RS
+.P
+Note that \fBeasterdate\fR computes the Western Easter.  For the Orthodox
+Easter date, see \fBorthodoxeaster\fR.
+.RE
 .TP
 .B evaltrig(s_trigger [,dq_start])
 Evaluates \fItrigger\fR as if it were a REM or IFTRIG trigger specification
@@ -3261,6 +3266,17 @@ the actual time, or a time supplied on the command line.
 Returns a string that is the ordinal number \fInum\fR.  For example,
 \fBord(2)\fR returns "2nd", and \fBord(213)\fR returns "213th".
 .TP
+.B orthodoxeaster(dqi_arg)
+If \fIarg\fR is an \fBINT\fR, then returns the date of Orthodox Easter Sunday
+for the specified year.  If \fIarg\fR is a \fBDATE\fR or
+\fBDATETIME\fR, then returns the date of the next Orthodox Easter Sunday on or
+after \fIarg\fR.  (The time component of a datetime is ignored.)
+.RS
+.P
+Note that \fBorthodoxeaster\fR computes the Orthodox Easter.  For the Western
+Easter date, see \fBeasterdate\fR.
+.RE
+.TP
 .B ostype()
 Returns "UNIX".  Remind used to run on OS/2 and MS-DOS, but does not
 any longer.

src/funcs.c

@@ -124,6 +124,7 @@ static int FNDusk          (func_info *);
 static int FNonomitted     (func_info *);
 static int FNow            (func_info *);
 static int FOrd            (func_info *);
+static int FOrthodoxeaster (func_info *);
 static int FOstype         (func_info *);
 static int FPad            (func_info *);
 static int FPlural         (func_info *);
@@ -288,6 +289,7 @@ BuiltinFunc Func[] = {
     {   "nonomitted",   2,      NO_MAX, 0,          FNonomitted },
     {   "now",          0,      0,      0,          FNow    },
     {   "ord",          1,      1,      1,          FOrd    },
+    {   "orthodoxeaster",1,     1,      0,          FOrthodoxeaster },
     {   "ostype",       0,      0,      1,          FOstype },
     {   "pad",          3,      4,      1,          FPad    },
     {   "plural",       1,      3,      1,          FPlural },
@@ -2292,6 +2294,45 @@ static int FEasterdate(func_info *info)
 
     return OK;
 }
+
+/****************************************************************/
+/*                                                              */
+/*  FOrthodoxeaster - calc. Orthodox easter Sunday              */
+/*                                                              */
+/*  From Meeus, Astronomical Algorithms                         */
+/*                                                              */
+/****************************************************************/
+static int FOrthodoxeaster(func_info *info)
+{
+    int y, m, d;
+    int a, b, c, dd, e, f, dse;
+    if (ARG(0).type == INT_TYPE) {
+	y = ARGV(0);
+	if (y < BASE) return E_2LOW;
+	else if (y > BASE+YR_RANGE) return E_2HIGH;
+    } else if (HASDATE(ARG(0))) {
+	FromDSE(DATEPART(ARG(0)), &y, &m, &d);  /* We just want the year */
+    } else return E_BAD_TYPE;
+
+    do {
+        a = y % 4;
+        b = y % 7;
+        c = y % 19;
+        dd = (19 * c + 15) % 30;
+        e = (2*a + 4*b - dd + 34) % 7;
+        f = dd + e + 114;
+        m = (f / 31) - 1;
+        d = (f % 31) + 1;
+
+        dse = DSE(y, m, d);
+        dse += JulianToGregorianOffset(y, m);
+	RetVal.type = DATE_TYPE;
+	RETVAL = dse;
+	y++;
+    } while (HASDATE(ARG(0)) && RETVAL < DATEPART(ARG(0)));
+
+    return OK;
+}
 /***************************************************************/
 /*                                                             */
 /*  FIsdst and FMinsfromutc                                    */

src/main.c

@@ -385,6 +385,23 @@ void FromDSE(int dse, int *y, int *m, int *d)
     return;
 }
 
+int JulianToGregorianOffset(int y, int m)
+{
+    int offset = 13;
+    int centuries;
+    int four_centuries;
+    if (y >= 2100) {
+        centuries = (y - 2000) / 100;
+        four_centuries = (y - 2000) / 400;
+        offset += centuries - four_centuries;
+        if (!(y%100) && (y % 400)) {
+            if (m < 2) {
+                offset--;  /* Offset increments in March */
+            }
+        }
+    }
+    return offset;
+}
 /***************************************************************/
 /*                                                             */
 /*  ParseChar                                                  */

src/protos.h

@@ -58,6 +58,7 @@ void InitRemind (int argc, char const *argv[]);
 void Usage (void);
 int DSE (int year, int month, int day);
 void FromDSE (int dse, int *y, int *m, int *d);
+int JulianToGregorianOffset(int y, int m);
 int ParseChar (ParsePtr p, int *err, int peek);
 int ParseToken (ParsePtr p, DynamicBuffer *dbuf);
 int ParseIdentifier (ParsePtr p, DynamicBuffer *dbuf);

tests/test.rem

@@ -383,6 +383,14 @@ msg [a077]%
 set a078 easterdate(today())
 set a079 easterdate(1992)
 set a080 easterdate(1995)
+set a078 orthodoxeaster(today())
+set a079 orthodoxeaster(1992)
+set a080 orthodoxeaster(1995)
+set a080 orthodoxeaster(2023)
+set a080 orthodoxeaster(2024)
+set a080 orthodoxeaster(2025)
+set a080 orthodoxeaster(2026)
+set a080 orthodoxeaster(2027)
 set a081 ""
 OMIT 1991-03-11
 set a082 slide('1991-03-01', 7, "Sat", "Sun")