---
title: "The date data type"
url: "https://docs.yugabyte.com/stable/api/ysql/datatypes/type_datetime/date-time-data-types-semantics/type-date/"
---

# The date data type

The semantics of the date data type. [YSQL]

Values whose data type is *date* represent the date component of some moment (the year, the month, and the day) in the "local" (a.k.a. "wall-clock") regime. *Date* values know nothing about timezones, and represent the date at some unspecified location. You can picture a *date* value as the number of days (or microseconds, if you prefer) to the start of the day in question from the start of some epoch—which number is then mapped using the [proleptic Gregorian calendar](https://www.postgresql.org/docs/15/datetime-units-history.html "proleptic Gregorian calendar") to a date in the familiar year-month-day representation.

Notice that subtracting one *date* value from another *date* value produces an *integer* value: the number of days between the two specified days. The value is sensitive to Gregorian calendar leap years. Try this:

```plpgsql
select pg_typeof('2019-02-14'::date - '2018-02-14'::date)::text as "data type of difference between dates";
```

This is the result:

```output
 data type of difference between dates
---------------------------------------
 integer
```

Notice that this example takes advantage of the fact that the value of any data type, *d*, can be *::text* typecast to a canonical representation and that a *text* value that uses the canonical representation format can be *::d* typecast to a *d* value—and that the round trip is non-lossy.

Now try this:

```plpgsql
select
  '2019-02-14'::date - '2017-02-14'::date as "not spanning a leap year",
  '2021-02-14'::date - '2019-02-14'::date as "spanning a leap year";
```

This is the result:

```output
 not spanning a leap year | spanning a leap year
--------------------------+----------------------
                      730 |                  731
```