You might have encountered a performance degrade for data reloads when using the function ConvertToLocalTime() only with one parameter "timestamp" since upgrade to QS Feb 2021 or/and QV 12.60 as reloads could take 3 times longer than with the previous version before the upgrade.
Environment
Qlik Sense February 2021, May 2021
QlikView 12.60, 12.60 SR1
Workaround:
Using the second parameter "place" in ConvertToLocalTime() improves the reload performance.
Cause
The described behaviour is related to a defect. The fix is was delivered for Qlik Sense Client Managed in November 2021 IR, August 2021 Patch 14, May 2021 Patch 9 and February 2021 Patch 14.