to transfer or switch something (such as a bill, payment, reservation, or schedule) to another date/account; to move over or reassign.
台風でコンサートが中止になり、チケットを別の日に振り替えた。
The concert was canceled due to the typhoon, and the tickets were transferred to another date.
給料の振込先を新しい口座に振り替える手続きをした。
I completed the procedure to transfer my salary deposits to a new account.
授業を来週に振り替えることになった。
The class was rescheduled/shifted to next week.