Backport from xs.

xs_time.h

@@ -0,0 +1,58 @@
+/* copyright (c) 2022 grunfink - MIT license */
+
+#ifndef _XS_TIME_H
+
+#define _XS_TIME_H
+
+#include <time.h>
+
+d_char *xs_str_time(time_t t, const char *fmt, int local);
+#define xs_str_localtime(t, fmt) xs_str_time(t, fmt, 1)
+#define xs_str_utctime(t, fmt)   xs_str_time(t, fmt, 0)
+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)
+
+#ifdef XS_IMPLEMENTATION
+
+d_char *xs_str_time(time_t t, const char *fmt, int local)
+/* returns a d_char with a formated time */
+{
+    struct tm tm;
+    char tmp[64];
+
+    if (t == 0)
+        t = time(NULL);
+
+    if (local)
+        localtime_r(&t, &tm);
+    else
+        gmtime_r(&t, &tm);
+
+    strftime(tmp, sizeof(tmp), fmt, &tm);
+
+//    printf("%d %d\n", local, t - xs_parse_time(tmp, fmt, local));
+
+    return xs_str_new(tmp);
+}
+
+
+char *strptime(const char *s, const char *format, struct tm *tm);
+
+time_t xs_parse_time(const char *str, const char *fmt, int local)
+{
+    struct tm tm;
+
+    memset(&tm, '\0', sizeof(tm));
+    strptime(str, fmt, &tm);
+
+    if (local)
+        tm.tm_isdst = -1;
+
+    return local ? mktime(&tm) : timegm(&tm);
+}
+
+
+#endif /* XS_IMPLEMENTATION */
+
+#endif /* _XS_TIME_H */