guile-examples/time/srfi-19-objects.scm

(import (srfi srfi-19))

(simple-format (current-output-port) "date: ~s\n" (current-date))
(simple-format (current-output-port) "date: ~s\n" (make-date 0 0 0 10 13 3 2021 0))
(simple-format (current-output-port) "time: ~s\n" (current-time time-utc))
(let* ([seconds 1]
       [minutes (* 60 seconds)]
       [hours (* 60 minutes)]
       [now (current-time time-utc)])
  (simple-format (current-output-port)
                 "duration: ~s\n"
                 (time-difference (add-duration now (make-time time-duration 0 (* 1 hours)))
                                  now)))