Which class to use to handle date & time & zone

A Very Fast Date Algorithm

Romans had March as the first month of the year, so leap day was the last day of the year and September, October, November and December were the 7th (sept), 8th (oct), ninth (nov) and 10th (dec) months.

• 30–40% faster / HN - Counting years backwards unlocks faster speed. The first date algorithm to use only 4 multiplications, instead of 7+.

ISO 8601 Format

Java

Instant vs LocalDateTime (Modern class vs Legacy class)