+int parse_time(const char *t, usec_t *usec, usec_t default_unit);
+#if 0 /// UNNEEDED by elogind
+int parse_nsec(const char *t, nsec_t *nsec);
+
+bool ntp_synced(void);
+
+int get_timezones(char ***l);
+bool timezone_is_valid(const char *name);
+
+#endif // 0
+bool clock_boottime_supported(void);
+bool clock_supported(clockid_t clock);
+#if 0 /// UNNEEDED by elogind
+clockid_t clock_boottime_or_monotonic(void);
+#endif // 0
+
+#define xstrftime(buf, fmt, tm) \
+ assert_message_se(strftime(buf, ELEMENTSOF(buf), fmt, tm) > 0, \
+ "xstrftime: " #buf "[] must be big enough")
+
+#if 0 /// UNNEEDED by elogind
+int get_timezone(char **timezone);
+
+time_t mktime_or_timegm(struct tm *tm, bool utc);
+#endif // 0
+struct tm *localtime_or_gmtime_r(const time_t *t, struct tm *tm, bool utc);