Group: Forum Members
I had this behavior back with Reflect 7.2 when I was using Windows Task Scheduler, because that was all that was available back then. In short, I had a schedule for monthly Fulls on the first day of each month, and what happened was that the schedule would run as expected, but would ALSO fire on the day before, i.e. the last day of the previous month. I changed that schedule to execute on the first Sunday of the month, and once again, it executed as expected AND on the day before the expected day.
In my case, switching to Macrium Task Scheduler when it became available starting with Reflect 7.3 immediately resolved the issue. I didn't even need to recreate my schedules. And I haven't had problems like that since then.
Others who have previously reported scheduling problems with Windows Task Scheduler related to transitions into and out of DST, such as all post-transition scheduled executions running at the wrong time or failing to run entirely, have found that switching to Macrium Task Scheduler resolved those issues too. I didn't have that problem with Reflect, but I did once support a client that used a different backup solution, and I found that its scheduled executions would all fail after a DST transition until its services were restarted.
Evidently scheduling engines can be tricky to write. And I guess in some ways that makes sense. Our calendar system is an utter mess from an engineer's perspective, with different months having different numbers of days, time zones, DST in some locations but not others (and DST transitions occurring at different points in the year for different locations), leap years that change the number of days in February and that themselves have convoluted logic to determine which years are leap years at all, and even leap SECONDS. That's why when I participated in a beta test of the Macrium Task Scheduler engine prior to its release in Reflect 7.3, I subjected it to all sorts of bizarre scenarios to try to break it. I found a variety of issues, some of which might never have been encountered in the real world, but Macrium fixed every last one of them prior to releasing Reflect 7.3, and I've seen little to no fixes related to Macrium Task Scheduler in the release notes of Reflect since then.