Is there a way to disable the "Custom Time" option in the "TimeRangePicker" module?
It's important that I can restrict the time range users can search on.
I am aware I can restrict the time range by applying restrictions by user role permissions, but this just confuses things for my users. They still can choose any arbitrary "Custom Time" range - but they are never warned if the range they have chosen exceeds the permitted time range for their role.
No I'm afraid there is currently no way. You can restrict all the other options by modifying times.conf, as long as you're OK with the changes affecting all roles and users and taking effect across an entire app rather than just certain views. However the "custom time" UI cannot be turned off.
Sideview Utils doesn't offer anything here either. Although I get a lot of requests to build a simple DateTimePicker and also a simple TimeRangePicker replacement, I haven't gotten to it yet. It is coming though and I will try to implement something sensible here for your use case.