1 files changed, 72 insertions, 0 deletions
diff --git a/newlib/libc/time/tzset.c b/newlib/libc/time/tzset.c
new file mode 100644
index 000000000..c70e3ee6e
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+++ b/newlib/libc/time/tzset.c
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+/*
+FUNCTION
+<<tzset>>---set timezone characteristics from TZ environment variable
+
+INDEX
+	tzset
+
+ANSI_SYNOPSIS
+	#include <time.h>
+	void tzset(void);
+	void _tzset_r (struct _reent *);
+
+TRAD_SYNOPSIS
+	#include <time.h>
+	void tzset();
+	void _tzset_r (reent_ptr)
+        struct _reent *reent_ptr;
+
+DESCRIPTION
+<<tzset>> examines the TZ environment variable and sets up the three
+external variables: <<_timezone>>, <<_daylight>>, and <<tzname>>.  The
+value of <<_timezone>> shall be the offset from the current time zone
+to GMT.  The value of <<_daylight>> shall be 0 if there is no daylight
+savings time for the current time zone, otherwise it will be non-zero.
+The <<tzname>> array has two entries: the first is the name of the
+standard time zone, the second is the name of the daylight-savings time
+zone.
+
+The TZ environment variable is expected to be in the following POSIX
+format:
+
+  stdoffset1[dst[offset2][,start[/time1],end[/time2]]]
+
+where: std is the name of the standard time-zone (minimum 3 chars)
+       offset1 is the value to add to local time to arrive at Universal time
+         it has the form:  hh[:mm[:ss]]
+       dst is the name of the alternate (daylight-savings) time-zone (min 3 chars)
+       offset2 is the value to add to local time to arrive at Universal time
+         it has the same format as the std offset
+       start is the day that the alternate time-zone starts
+       time1 is the optional time that the alternate time-zone starts
+         (this is in local time and defaults to 02:00:00 if not specified)
+       end is the day that the alternate time-zone ends
+       time2 is the time that the alternate time-zone ends
+         (it is in local time and defaults to 02:00:00 if not specified)
+
+Note that there is no white-space padding between fields.  Also note that
+if TZ is null, the default is Universal GMT which has no daylight-savings
+time.  If TZ is empty, the default EST5EDT is used.
+
+The function <<_tzset_r>> is identical to <<tzset>> only it is reentrant
+and is used for applications that use multiple threads.
+
+RETURNS
+There is no return value.
+
+PORTABILITY
+<<tzset>> is part of the POSIX standard.
+
+Supporting OS subroutine required: None
+*/
+
+#include <_ansi.h>
+#include <reent.h>
+#include <time.h>
+#include "local.h"
+
+_VOID
+_DEFUN_VOID (tzset)
+{
+  _tzset_r (_REENT);
+}