-char *format_timestamp_pretty(char *buf, size_t l, usec_t t);
-char *format_timespan(char *buf, size_t l, usec_t t);
+char *format_timestamp_us(char *buf, size_t l, usec_t t);
+char *format_timestamp_relative(char *buf, size_t l, usec_t t);
+char *format_timespan(char *buf, size_t l, usec_t t, usec_t accuracy);