+bool ntp_synced(void);
+
+int get_timezones(char ***l);
+bool timezone_is_valid(const char *name);
+
+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")