What does DATE_TRUNC do to the time?

Question

Accepted Answer

DATE_TRUNC(field, timestamp) rounds the timestamp down to the start of the specified unit. Truncating to 'month' sets the day to 1 and time to 00:00:00, giving 2024-07-01 00:00:00. Truncating to 'year' would give 2024-01-01 00:00:00; to 'day' would give 2024-07-15 00:00:00. This is the standard way to group data by month or year in PostgreSQL.