Calculate difference between dates - Postgres

Question

I have a requirement to calculate the number of days from 3 different dates. I need to run the logic to get an integer value from below pseudo logic.

(future_date_1 - future_date_2) - Today()

How to achieve this in PostgreSQL?

You need to be more precise, what exactly you need? the day value of a date; the numeric count of a date since 1900 in milliseconds; the number of days between date_1, date_2, and today? be more specific please. — Dan
– Dan, Commented Sep 13, 2017 at 18:23
This question does not seem to makes sense. An integer cannot express days between 3 dates. You would need to clarify. And all the basic information like data types and Postgres version are missing. too. — Erwin Brandstetter
– Erwin Brandstetter, Commented Sep 13, 2017 at 19:59
edit your question and add some sample data and the expected output based on that data. Formatted text please, no screen shots. Do not post code or additional information in comments — user330315
– user330315, Commented Sep 13, 2017 at 21:37

bigbounty · Accepted Answer · 2017-09-13 21:36:51Z

5

In order to achieve the date difference in days,

SELECT DATE_PART('day', '2011-12-31 01:00:00'::timestamp - '2011-12-29 23:00:00'::timestamp);

OR

this also works pretty well

select '2015-01-12'::date - '2015-01-01'::date;

Now, you only need to use this logic and satisfy your requirement.

user330315

answered Sep 13, 2017 at 18:21

bigbounty

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