1 files changed, 124 insertions, 0 deletions

diff --git a/xs_time.h b/xs_time.h
index 0e004dc..a5792bc 100644
--- a/xs_time.h
+++ b/xs_time.h
@@ -15,6 +15,8 @@ time_t xs_parse_time(const char *str, const char *fmt, int local);
 #define xs_parse_localtime(str, fmt) xs_parse_time(str, fmt, 1)
 #define xs_parse_utctime(str, fmt) xs_parse_time(str, fmt, 0)
 xs_str *xs_str_time_diff(time_t time_diff);
+xs_list *xs_tz_list(void);
+int xs_tz_offset(const char *tz);
 
 #ifdef XS_IMPLEMENTATION
 
@@ -106,6 +108,128 @@ time_t xs_parse_iso_date(const char *iso_date, int local)
 }
 
 
+/** timezones **/
+
+/* intentionally dead simple */
+
+struct {
+    const char *tz; /* timezone name */
+    float h_offset; /* hour offset */
+} xs_tz[] = {
+    { "UTC",                                     0 },
+    { "WET (Western European Time)",             0 },
+    { "WEST (Western European Summer Time)",     1 },
+    { "CET (Central European Time)",             1 },
+    { "CEST (Central European Summer Time)",     2 },
+    { "EET (Eastern European Time)",             2 },
+    { "EEST (Eastern European Summer Time)",     3 },
+    { "MSK (Moskow Time Zone)",                  3 },
+    { "EST (Eastern Time Zone)",                 -5 },
+    { "AST (Atlantic Time Zone)",                -4 },
+    { "ADT (Atlantic Daylight Time Zone)",       -3 },
+    { "CST (Central Time Zone)",                 -6 },
+    { "CDT (Central Daylight Time Zone)",        -5 },
+    { "MST (Mountain Time Zone)",                -7 },
+    { "MDT (Mountain Daylight Time Zone)",       -6 },
+    { "PST (Pacific Time Zone)",                 -8 },
+    { "PDT (Pacific Daylight Time Zone)",        -7 },
+    { "AKST (Alaska Time Zone)",                 -9 },
+    { "AKDT (Alaska Daylight Time Zone)",        -8 },
+    { "China Time Zone",                         8 },
+    { "IST (Israel Standard Time)",              2 },
+    { "IDT (Israel Daylight Standard Time)",     3 },
+    { "WIB (Western Indonesia Time)",            7 },
+    { "WITA (Central Indonesia Time)",           8 },
+    { "WIT (Eastern Indonesia Time)",            9 },
+    { "AWST (Australian Western Time)",          8 },
+    { "ACST (Australian Eastern Time)",          9.5 },
+    { "ACDT (Australian Daylight Eastern Time)", 10.5 },
+    { "AEST (Australian Eastern Time)",          10 },
+    { "AEDT (Australian Daylight Eastern Time)", 11 },
+    { "NZST (New Zealand Time)",                 12 },
+    { "NZDT (New Zealand Daylight Time)",        13 },
+    { "UTC",      0 },
+    { "UTC+1",    1 },
+    { "UTC+2",    2 },
+    { "UTC+3",    3 },
+    { "UTC+4",    4 },
+    { "UTC+5",    5 },
+    { "UTC+6",    6 },
+    { "UTC+7",    7 },
+    { "UTC+8",    8 },
+    { "UTC+9",    9 },
+    { "UTC+10",   10 },
+    { "UTC+11",   11 },
+    { "UTC+12",   12 },
+    { "UTC-1",    -1 },
+    { "UTC-2",    -2 },
+    { "UTC-3",    -3 },
+    { "UTC-4",    -4 },
+    { "UTC-5",    -5 },
+    { "UTC-6",    -6 },
+    { "UTC-7",    -7 },
+    { "UTC-8",    -8 },
+    { "UTC-9",    -9 },
+    { "UTC-10",   -10 },
+    { "UTC-11",   -11 },
+    { "UTC-12",   -12 },
+    { "UTC-13",   -13 },
+    { "UTC-14",   -14 },
+    { "GMT",      0 },
+    { "GMT+1",    -1 },
+    { "GMT+2",    -2 },
+    { "GMT+3",    -3 },
+    { "GMT+4",    -4 },
+    { "GMT+5",    -5 },
+    { "GMT+6",    -6 },
+    { "GMT+7",    -7 },
+    { "GMT+8",    -8 },
+    { "GMT+9",    -9 },
+    { "GMT+10",   -10 },
+    { "GMT+11",   -11 },
+    { "GMT+12",   -12 },
+    { "GMT-1",    1 },
+    { "GMT-2",    2 },
+    { "GMT-3",    3 },
+    { "GMT-4",    4 },
+    { "GMT-5",    5 },
+    { "GMT-6",    6 },
+    { "GMT-7",    7 },
+    { "GMT-8",    8 },
+    { "GMT-9",    9 },
+    { "GMT-10",   10 },
+    { "GMT-11",   11 },
+    { "GMT-12",   12 },
+    { "GMT-13",   13 },
+    { "GMT-14",   14 },
+    { NULL,       0 }
+};
+
+
+xs_list *xs_tz_list(void)
+/* returns the list of supported timezones */
+{
+    xs_list *l = xs_list_new();
+
+    for (int n = 0; xs_tz[n].tz != NULL; n++)
+        l = xs_list_append(l, xs_tz[n].tz);
+
+    return l;
+}
+
+
+int xs_tz_offset(const char *tz)
+/* returns the offset in seconds from the specified Time Zone to UTC */
+{
+    for (int n = 0; xs_tz[n].tz != NULL; n++) {
+        if (strcmp(xs_tz[n].tz, tz) == 0)
+            return xs_tz[n].h_offset * 3600;
+    }
+
+    return 0;
+}
+
+
 #endif /* XS_IMPLEMENTATION */
 
 #endif /* _XS_TIME_H */