Github has a hidden feature for comparing branches. This is the format used:
github.com/user/repo/compare/{range}
Where {range} is usually master...my-branch.
You can also target branches at specific point in time with time helpers. To
see what has changed in master in the past 24 hours, you can use this:
github.com/user/repo/compare/master@{1.day.ago}...master
There's a helper for yesterday:
github.com/user/repo/compare/master@{yesterday}...master
It supports dates too:
github.com/user/repo/compare/master@{2020-04-01}...master