Add a non-standard option that affects the output TZ only. The input (for

parsing) TZ is unaffected.  This makes it it easier to convert timestamps
from any timezone to any other timezone -- no need for $() gymnastics
ok millert

2 files changed, 23 insertions, 8 deletions

diff --git a/bin/date/date.1 b/bin/date/date.1
index e6b96016caf..09be59bf0a9 100644
--- a/bin/date/date.1
+++ b/bin/date/date.1
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: date.1,v 1.54 2010/09/19 20:55:25 jmc Exp $
+.\"	$OpenBSD: date.1,v 1.55 2011/03/11 18:22:49 deraadt Exp $
 .\"	$NetBSD: date.1,v 1.12 1996/03/12 04:32:37 phil Exp $
 .\"
 .\" Copyright (c) 1980, 1990, 1993
@@ -33,7 +33,7 @@
 .\"
 .\"     @(#)date.1	8.3 (Berkeley) 4/28/95
 .\"
-.Dd $Mdocdate: September 19 2010 $
+.Dd $Mdocdate: March 11 2011 $
 .Dt DATE 1
 .Os
 .Sh NAME
@@ -45,6 +45,7 @@
 .Op Fl d Ar dst
 .Op Fl r Ar seconds
 .Op Fl t Ar minutes_west
+.Op Fl z Ar output_zone
 .Op Cm + Ns Ar format
 .Sm off
 .Oo Oo Oo Oo Oo Oo
@@ -112,6 +113,14 @@ by future calls to
 .Xr gettimeofday 2 .
 .It Fl u
 Display or set the date in UTC (Coordinated Universal) time.
+.It Fl z Ar output_zone
+Just before printing the time, change to the specified timezone;
+see the description of
+.Ev TZ
+below.
+This can be used with
+.Fl j
+to easily convert time specifications from one zone to another.
 .El
 .Pp
 An operand with a leading plus sign
@@ -159,7 +168,7 @@ and leap years are handled automatically.
 .Sh ENVIRONMENT
 .Bl -tag -width Ds
 .It Ev TZ
-The time zone to use when displaying dates.
+The time zone to use when parsing or displaying dates.
 See
 .Xr environ 7
 for more information.
diff --git a/bin/date/date.c b/bin/date/date.c
index 022ef1c59cc..891e6313fcd 100644
--- a/bin/date/date.c
+++ b/bin/date/date.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: date.c,v 1.34 2011/03/11 17:11:15 deraadt Exp $	*/
+/*	$OpenBSD: date.c,v 1.35 2011/03/11 18:22:49 deraadt Exp $	*/
 /*	$NetBSD: date.c,v 1.11 1995/09/07 06:21:05 jtc Exp $	*/
 
 /*
@@ -63,13 +63,13 @@ main(int argc, char *argv[])
 {
 	struct timezone tz;
 	int ch, rflag;
-	char *format, buf[1024];
+	char *format, buf[1024], *outzone = NULL;
 
 	setlocale(LC_ALL, "");
 
 	tz.tz_dsttime = tz.tz_minuteswest = 0;
 	rflag = 0;
-	while ((ch = getopt(argc, argv, "ad:jnr:ut:")) != -1)
+	while ((ch = getopt(argc, argv, "ad:jnr:ut:z:")) != -1)
 		switch((char)ch) {
 		case 'd':		/* daylight saving time */
 			tz.tz_dsttime = atoi(optarg) ? 1 : 0;
@@ -98,6 +98,9 @@ main(int argc, char *argv[])
 				break;
 			}
 			/* FALLTHROUGH */
+		case 'z':
+			outzone = optarg;
+			break;
 		default:
 			usage();
 		}
@@ -138,6 +141,9 @@ main(int argc, char *argv[])
 	if (argc > 0)
 		errx(1, "too many arguments");
 
+	if (outzone)
+		setenv("TZ", outzone, 1);
+
 	(void)strftime(buf, sizeof(buf), format, localtime(&tval));
 	(void)printf("%s\n", buf);
 	exit(retval);
@@ -270,9 +276,9 @@ static void
 usage(void)
 {
 	(void)fprintf(stderr,
-	    "usage: %s [-ajnu] [-d dst] [-r seconds] [-t minutes_west] [+format]\n",
+	    "usage: %s [-ajnu] [-d dst] [-r seconds] [-t minutes_west] [-z output_zone]\n",
 	     __progname);
 	(void)fprintf(stderr,
-	    "%-*s[[[[[[cc]yy]mm]dd]HH]MM[.SS]]\n", (int)strlen(__progname) + 8, "");
+	    "%-*s[+format] [[[[[[cc]yy]mm]dd]HH]MM[.SS]]\n", (int)strlen(__progname) + 8, "");
 	exit(1);
 }