SQL
Equality and Comparison
For equality and ordering comparisons only, the total number of microseconds in an `INTERVAL` is computed by converting the days basis unit to `24 * 60 * 60 * 1e6` microseconds and the months basis unit to 30 days, or `30 * 24 * 60 * 60 * 1e6` microseconds.  
As a result, `INTERVAL`s can compare equal even when they are functionally different, and the ordering of `INTERVAL`s is not always preserved when they are added to dates or timestamps.  
For example:  
* `INTERVAL 30 DAYS = INTERVAL 1 MONTH`
* but `DATE '2020-01-01' + INTERVAL 30 DAYS != DATE '2020-01-01' + INTERVAL 1 MONTH`.  
and  
* `INTERVAL '30 days 12 hours' > INTERVAL 1 MONTH`
* but `DATE '2020-01-01' + INTERVAL '30 days 12 hours' < DATE '2020-01-01' + INTERVAL 1 MONTH`.