Documentation

## Compare Dates and Time

This example shows how to compare `datetime` and `duration` arrays. You can perform an element-by-element comparison of values in two `datetime` arrays or two `duration` arrays using relational operators, such as `>` and `<`.

### Compare Datetime Arrays

Compare two `datetime` arrays. The arrays must be the same size or one can be a scalar.

`A = datetime(2013,07,26) + calyears(0:2:6)`
```A = 1x4 datetime array 26-Jul-2013 26-Jul-2015 26-Jul-2017 26-Jul-2019 ```
`B = datetime(2014,06,01)`
```B = datetime 01-Jun-2014 ```
`A < B`
```ans = 1x4 logical array 1 0 0 0 ```

The `<` operator returns logical `1` (true) where a datetime in `A` occurs before a datetime in `B`.

Compare a `datetime` array to text representing a date.

`A >= 'September 26, 2014'`
```ans = 1x4 logical array 0 1 1 1 ```

Comparisons of `datetime` arrays account for the time zone information of each array.

Compare September 1, 2014 at 4:00 p.m. in Los Angeles with 5:00 p.m. on the same day in New York.

```A = datetime(2014,09,01,16,0,0,'TimeZone','America/Los_Angeles',... 'Format','dd-MMM-yyyy HH:mm:ss Z')```
```A = datetime 01-Sep-2014 16:00:00 -0700 ```
```B = datetime(2014,09,01,17,0,0,'TimeZone','America/New_York',... 'Format','dd-MMM-yyyy HH:mm:ss Z')```
```B = datetime 01-Sep-2014 17:00:00 -0400 ```
`A < B`
```ans = logical 0 ```

4:00 p.m. in Los Angeles occurs after 5:00 p.m. on the same day in New York.

### Compare Durations

Compare two `duration` arrays.

`A = duration([2,30,30;3,15,0])`
```A = 2x1 duration array 02:30:30 03:15:00 ```
`B = duration([2,40,0;2,50,0])`
```B = 2x1 duration array 02:40:00 02:50:00 ```
`A >= B`
```ans = 2x1 logical array 0 1 ```

Compare a duration array to a numeric array. Elements in the numeric array are treated as a number of fixed-length (24-hour) days.

`A < [1; 1/24]`
```ans = 2x1 logical array 1 0 ```

### Determine if Dates and Time Are Contained Within an Interval

Use the `isbetween` function to determine whether values in a `datetime` array lie within a closed interval.

Define endpoints of an interval.

`tlower = datetime(2014,08,01)`
```tlower = datetime 01-Aug-2014 ```
`tupper = datetime(2014,09,01)`
```tupper = datetime 01-Sep-2014 ```

Create a `datetime` array and determine whether the values lie within the interval bounded by `t1` and `t2`.

`A = datetime(2014,08,21) + calweeks(0:2)`
```A = 1x3 datetime array 21-Aug-2014 28-Aug-2014 04-Sep-2014 ```
`tf = isbetween(A,tlower,tupper)`
```tf = 1x3 logical array 1 1 0 ```