The results are intervals, which tell us the difference between the two timestamps:

0 years 0 mons 1673 days 23 hours 16 mins 0.00 secs

PostgresSQL provides the interval data type. The simplest way to create an interval in with the syntax:

INTERVAL 'x field'

x is a number, its unit can be any of millennium, century, decade, year, month, week, day, hour, minute, second, millisecond, microsecond, or abbreviations (y, m, d, etc.) or plural forms (months, days, etc.). Example intervals can be:

• INTERVAL '2 hours'
• INTERVAL '3 days'
• INTERVAL '5 months'
• INTERVAL '1 year'

You can add such intervals to a date/timestamp:

SELECT
  id,
  launched_timestamp,
  launched_timestamp + INTERVAL '1 year' AS new_launched_timestamp
FROM aircraft;

The above query will add one year to each launched timestamp in the aircraft table.