(import (chicken condition)
        (srfi 19))

(define (try-pattern input pattern)
    (call/cc
        (lambda (k)
            (with-exception-handler (lambda (x) (k #f))
                                    (string->date input pattern)))))

(define (parse-timestamp timestamp)
    (or (try-pattern timestamp "~H:~M:~S")
        (try-pattern timestamp "~Y-~m-~e")
        (try-pattern timestamp "~Y-~m-~e ~H:~M:~S")))
        
(parse-timestamp "2022-10-14")