Data Transfers · Scheduling transfers
What happens to a monthly transfer scheduled for the 31st in a shorter month?
Short answer: It runs on the last day of the month instead — for example 28 or 29 February — and goes back to the 31st when a month has one. Times use your Mac's local time in quarter-hour steps.
It runs on the last day of that month instead. A transfer set for the 31st runs on 28 or 29 February, 30 April and so on, then returns to the 31st in months that have one.
Times are set in your Mac's local time, with the hour and the minute picked separately; minutes come in quarter-hour steps (:00, :15, :30, :45). The Next run line under the picker shows exactly when the next run will be, so you can check before starting.
Related: Schedule a transfer