How to block editing of converted time cards prior to go live date.

Summary

When we go live in cloud HCM we have a need to read the time cards loaded from the legacy system for consecutive differentials.

Content

We are loading the converted timecards through rest API. However we have the issue that the time cards are editable and the edited segments are getting transferred to payroll. We want to know of any work arounds used by other customers to achieve this which will help all the Time cards loaded or entered prior to the go live date to be non editable. We tried using the number of days in Time Entry Profile however, this locks down the card based on rolling no of days and doesn't work for us and we need to have the ability to edit atleast