diff options
Diffstat (limited to 'lisp/calendar/time-date.el')
| -rw-r--r-- | lisp/calendar/time-date.el | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/lisp/calendar/time-date.el b/lisp/calendar/time-date.el index 4fbb3c59476..35c89a2ceac 100644 --- a/lisp/calendar/time-date.el +++ b/lisp/calendar/time-date.el @@ -386,7 +386,10 @@ decreased to be valid (\"add one month\" to January 31st will yield a result of February 28th (or 29th, depending on the leap year status). -Fields are added in a most to least significant order." +Fields are added in a most to least significant order. + +When changing the time bits in TIME (i.e., second/minute/hour), +changes in daylight saving time are not taken into account." (let ((time (copy-sequence time)) seconds) ;; Years are simple. @@ -399,7 +402,7 @@ Fields are added in a most to least significant order." (setf (decoded-time-month time) (mod new 12)) (cl-incf (decoded-time-year time) (/ new 12)))) - ;; Adjust for month length. + ;; Adjust for month length (as described in the doc string). (setf (decoded-time-day time) (min (date-days-in-month (decoded-time-year time) (decoded-time-month time)) @@ -427,6 +430,7 @@ Fields are added in a most to least significant order." time)) (defun decoded-time--alter-month (time increase) + "Increase or decrease the month in TIME by 1." (if increase (progn (cl-incf (decoded-time-month time)) @@ -439,6 +443,7 @@ Fields are added in a most to least significant order." (cl-decf (decoded-time-year time))))) (defun decoded-time--alter-day (time increase) + "Increase or decrease the day in TIME by 1." (if increase (progn (cl-incf (decoded-time-day time)) @@ -455,6 +460,7 @@ Fields are added in a most to least significant order." (decoded-time-month time)))))) (defun decoded-time--alter-second (time seconds increase) + "Increase or decrease the time in TIME by SECONDS." (let ((old (+ (* (or (decoded-time-hour time) 0) 3600) (* (or (decoded-time-minute time) 0) 60) (or (decoded-time-second time) 0)))) |