# leapseconds

List all leap seconds supported by `datetime` data type

## Syntax

``T = leapseconds``
``[T,vers] = leapseconds``

## Description

example

````T = leapseconds` returns a timetable containing a list of the leap seconds that the `datetime` data type supports. For each leap second, the timetable includes the date on which it occurred, its sign, and the cumulative number of leap seconds as of that date.To account for leap seconds in dates and times, create a `datetime` array by using the `datetime` function, and then specify the value of the `'TimeZone'` name-value pair argument as `'UTCLeapSeconds'`.```

example

````[T,vers] = leapseconds` returns the International Earth Rotation and Reference Systems Service (IERS) Bulletin C version number of the leap second data being used in MATLAB®. The IERS periodically declares new leap seconds as needed. For more information, see the IERS Bulletins.```

## Examples

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Create a timetable that lists all leap seconds that the `datetime` data type supports.

`T = leapseconds`
```T=27×2 timetable Date Type CumulativeAdjustment ___________ ____ ____________________ 30-Jun-1972 + 1 sec 31-Dec-1972 + 2 sec 31-Dec-1973 + 3 sec 31-Dec-1974 + 4 sec 31-Dec-1975 + 5 sec 31-Dec-1976 + 6 sec 31-Dec-1977 + 7 sec 31-Dec-1978 + 8 sec 31-Dec-1979 + 9 sec 30-Jun-1981 + 10 sec 30-Jun-1982 + 11 sec 30-Jun-1983 + 12 sec 30-Jun-1985 + 13 sec 31-Dec-1987 + 14 sec 31-Dec-1989 + 15 sec 31-Dec-1990 + 16 sec ⋮ ```

Determine if any leap seconds were added in the year 2008.

First, create a timetable of leap seconds.

`T = leapseconds`
```T=27×2 timetable Date Type CumulativeAdjustment ___________ ____ ____________________ 30-Jun-1972 + 1 sec 31-Dec-1972 + 2 sec 31-Dec-1973 + 3 sec 31-Dec-1974 + 4 sec 31-Dec-1975 + 5 sec 31-Dec-1976 + 6 sec 31-Dec-1977 + 7 sec 31-Dec-1978 + 8 sec 31-Dec-1979 + 9 sec 30-Jun-1981 + 10 sec 30-Jun-1982 + 11 sec 30-Jun-1983 + 12 sec 30-Jun-1985 + 13 sec 31-Dec-1987 + 14 sec 31-Dec-1989 + 15 sec 31-Dec-1990 + 16 sec ⋮ ```

Create a time range object whose start and end times cover the year 2008.

`tr = timerange('2008','year')`
```tr = timetable timerange subscript: Select timetable rows with times in: YEARS Starting at, including: 01-Jan-2008 00:00:00 Ending at, but excluding: 01-Jan-2009 00:00:00 See Select Times in Timetable. ```

To return rows of `T` whose times are within the year 2008, index into `T` by using `tr`. When you index into a timetable, you can specify rows by row number or by their row times.

`T(tr,:)`
```ans=1×2 timetable Date Type CumulativeAdjustment ___________ ____ ____________________ 31-Dec-2008 + 24 sec ```

List the IERS Bulletin C version number of the leap second data being used in MATLAB.

```[T,vers] = leapseconds; vers```
```vers = 64 ```

## Output Arguments

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List of leap seconds, returned as a timetable.

IERS Bulletin C version number, returned as an integer.

## Version History

Introduced in R2020a