Function dateDiff() calculates the difference of two time values (end time minus start time) and returns that value (take the integer part).

Arguments：

• End time <datetime | timestamp | string>
• Start time <datetime | timestamp | string>
• Unit <string>, valid options: day, hour, minute, second

Returns：

• Time difference <number>

Common Usage

Example: Direct calculate

uncollect ["2023-04-30 22:00:00", "2023-01-15 22:00:00"] as a
uncollect ["2023-04-28 22:00:00", "2023-01-15 23:00:00"] as b
uncollect ["day", "minute"] as c
return table(a, b, c, dateDiff(a, b, c))

|          a          |          b          |    c   | dateDiff(a, b, c) |
|---------------------|---------------------|--------|-------------------|
| 2023-04-30 22:00:00 | 2023-04-28 22:00:00 | day    | 2                 |
| 2023-01-15 22:00:00 | 2023-01-15 23:00:00 | minute | -60               |

Example: Multiply and calculate

uncollect ["2023-04-30 22:00:00", "2023-01-15 22:00:00"] as a
uncollect ["2023-04-28 22:00:00", "2023-01-15 23:00:00"] as b
uncollect ["day", "minute"] as c
with dateDiff(a, b, c) as d
return table(a, b, c, d)

|          a          |          b          |    c   |    d    |
|---------------------|---------------------|--------|---------|
| 2023-04-30 22:00:00 | 2023-04-28 22:00:00 | day    | 2       |
| 2023-04-30 22:00:00 | 2023-04-28 22:00:00 | minute | 2880    |
| 2023-04-30 22:00:00 | 2023-01-15 23:00:00 | day    | 104     |
| 2023-04-30 22:00:00 | 2023-01-15 23:00:00 | minute | 151140  |
| 2023-01-15 22:00:00 | 2023-04-28 22:00:00 | day    | -103    |
| 2023-01-15 22:00:00 | 2023-04-28 22:00:00 | minute | -148320 |
| 2023-01-15 22:00:00 | 2023-01-15 23:00:00 | day    | 0       |
| 2023-01-15 22:00:00 | 2023-01-15 23:00:00 | minute | -60     |