Introduce datetime->unix-time and back.

2 files changed, 11 insertions, 0 deletions

diff --git a/module/datetime.scm b/module/datetime.scm
index 30fb6025..0b3179ee 100644
--- a/module/datetime.scm
+++ b/module/datetime.scm
@@ -98,6 +98,7 @@
 ;; NOTE there isn't any stable way to craft the tm objects.
 ;; I could call mktime on some date, and replace the fields
 ;; with the set-tm:*, but that is worse that breaking the API.
+;; TODO TZ!
 (define (datetime->tm datetime)
   (let ((t (get-time% datetime))
         (d (get-date  datetime)))
@@ -113,6 +114,7 @@
             #f                 ; TZ name
             )))
 
+;; TODO TZ
 (define (tm->datetime tm)
   (datetime year:   (+ 1900 (tm:year tm))
             month:  (1+ (tm:mon  tm))
@@ -121,6 +123,14 @@
             minute: (tm:min  tm)
             second: (tm:sec  tm)))
 
+(define-public (datetime->unix-time dt)
+  (car (mktime (datetime->tm dt))))
+
+(define-public (unix-time->datetime n)
+  (tm->datetime (gmtime n)))
+
+;; TODO prodedure to change TZ for datetime object
+
 
 ;; datetime → datetime
 ;; Takes a datetime in any timezone, and renormalize it to local time
diff --git a/module/datetime/util.scm b/module/datetime/util.scm
index 059308e6..a3e4eacc 100644
--- a/module/datetime/util.scm
+++ b/module/datetime/util.scm
@@ -133,6 +133,7 @@
                    ((#\m) (format #t "~2'0d" (month date)))
                    ((#\d) (format #t "~2'0d" (day date)))
                    ;; Should be same as ~_d
+                   ((#\s) (display (datetime->unix-time datetime))) ; epoch time!
                    ((#\e) (format #t "~2' d" (day date)))
                    ((#\1) (format #t "~4'0d-~2'0d-~2'0d"
                                   (year date) (month date) (day date)))