DateTime.diff

You're seeing just the function diff, go back to DateTime module for more information.
Link to this function

diff(datetime1, datetime2, unit \\ :second)

View Source (since 1.5.0)

Specs

Subtracts datetime2 from datetime1.

The answer can be returned in any unit available from System.time_unit/0.

Leap seconds are not taken into account.

This function returns the difference in seconds where seconds are measured according to Calendar.ISO.

Examples

iex> dt1 = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "AMT",
...>                 hour: 23, minute: 0, second: 7, microsecond: {0, 0},
...>                 utc_offset: -14400, std_offset: 0, time_zone: "America/Manaus"}
iex> dt2 = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "CET",
...>                 hour: 23, minute: 0, second: 7, microsecond: {0, 0},
...>                 utc_offset: 3600, std_offset: 0, time_zone: "Europe/Warsaw"}
iex> DateTime.diff(dt1, dt2)
18000
iex> DateTime.diff(dt2, dt1)
-18000