E.g: uint8, uint16, uint32, uint64, uint128, uint256? Which of these is best recommended to future-proof the application? And given each uint, what year is the furthest it could be stored?
In the Yellow Paper the block's timestamp is storead as a scalar integer less than 2256.
If you do not care about space then an uint256 should be good enough for your future needs.
- Using uint8 should be good until '1970-01-01T00:04:15+00:00'
- Using uint16 should be good until '1970-01-01T18:12:15+00:00'
- Using uint32 should be good enough until '2106-02-07T06:28:15+00:00'
- Using uint64 should be good for 584,942,417,355 years after 1970