Lock Entries past certain timeframe

Is it possible to lock the ability to enter charges past a certain time frame?

We would like to disable the ability for staff to charge time after a certain time, is this possible?

Thank you for posting this.

In case you refer to adding the Charges when the pre-paid hours were fully used, then it can be achieved by using Block of Time Contracts.
Hourly Charges (Labor) logged under such Contract are deducted from the block and when adding the charge that exceeds the hours block, the user is warned about it.

Hope this helps.

A warning does not really help.

We just don't want to allow technicians to change time after it has been billed.

​There is no option to avoid a user from editing the charge, unless the charge is marked as billed and becomes read​-​only.
The charges are marked as billed automatically when included in the QuickBooks/Xer​o​ invoice generated from RangerMSP. It is also possible to set the charge as billed manually using the button in the ​C​harges window or using ​'​Mark all as billed' under the Charges tab​:​