Added log name helpers

tk/mcron.scm

@@ -31,3 +31,19 @@
 (define (step-from base step tm)
   (let ((steps (euclidean-quotient (- tm base) step)))
     (+ base (* step (+ 1 steps)))))
+
+;;;;;;;;;;;;;;;;;;;
+;; Logging Utility
+(define (current-date-string)
+  (let ((ct (current-time)))
+    (string-append (number->string (date-year  ct)) "-"
+                   (number->string (date-month ct)) "-"
+                   (number->string (date-day   ct)))))
+
+(define (yesterday-date-string)
+  (let* ((day (make-time time-duration 0 sec/day))
+         (ct (subtract-duration! (current-time) day)))
+    (string-append (number->string (date-year  ct)) "-"
+                   (number->string (date-month ct)) "-"
+                   (number->string (date-day   ct)))))
+;;;;;;;;;;;;;;;;;;;