work with dates before 1900 or timestamp before 1970

[aceforeverd]

One approach: both type are string from storage, following a standard like ISO 8601. The SQL execute engine parse it into the date and timestamp type that supports it, which are the internal structure do not counts to user

[aceforeverd]

For date type in storage: the year field is stored in 16bit, consider sufficient for year in range 1900 + [-2^15, 2^15-1]

[aceforeverd]

for timestamp, typically stored as a 64-bit integer representing seconds since the "Unix epoch" of 1970-01-01 00:00:00 UTC. Positive integers are times after the epoch, negative before