When creating a world, 'Do Daylight Cycle' and 'Always Day' can both be disabled. This is intentional, but when 'Always Day' is clicked at least once, they can no longer both be disabled.

To Reproduce:

1. Start creating a new world and enable cheats.
2. Disable 'Do Daylight Cycle'. Notice that 'Always Day' is unaffected.
3. Enable 'Do Daylight Cycle'. Notice that 'Always Day' is unaffected.
4. Enable 'Always Day'. Notice that 'Do Daylight Cycle' is disabled as a result.
5. Disable 'Always Day'. Notice that 'Do Daylight Cycle' is enabled as a result. Also notice that the two settings are at their default values now.
6. Disable 'Do Daylight Cycle'. Notice that unlike in step 1, 'Always Day' is enabled as a result.