SQL Server has functions for modifying a date, such as DATEADD(…)
Postgres has an interval type which allows you to add/remove in a much more semantic manner.
For example, in SQL Server to add 5 days to the current date we might do:
SELECT DATEADD(day, 5, getutcdate())
In Postgres we would achieve the same like so:
SELECT now() + ‘5 days’::interval;