Dates and Time

Arrays of date and time values that can be displayed in different formats

The date and time data typesdatetime,duration, andcalendarDurationsupport efficient computations, comparisons, and formatted display of dates and times. Work with these arrays in the same way that you work with numeric arrays. You can add, subtract, sort, compare, concatenate, and plot date and time values. You also can represent dates and times as numeric arrays or as text. For more information, seeRepresent Dates and Times in MATLABor watchDate and Time Arrays.

Functions

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Create Date and Time Arrays

Points in Time

`datetime`	Arrays that represent points in time
`dateshift`	Shift date or generate sequence of dates and times
`NaT`	Not-a-Time
`eomday`	Last day of month
`lweekdate`	Date of last occurrence of weekday in month
`nweekdate`	Date of specific occurrence of weekday in month

Durations

`一年s`	Duration in years
`days`	Duration in days
`hours`	Duration in hours
`minutes`	Duration in minutes
`seconds`	Duration in seconds
`milliseconds`	Duration in milliseconds
`duration`	Lengths of time in fixed-length units

Calendar Durations

`calyears`	Calendar duration in years
`calquarters`	Calendar duration in quarters
`calmonths`	Calendar duration in months
`calweeks`	Calendar duration in weeks
`caldays`	Calendar duration in days
`calendarDuration`	Lengths of time in variable-length calendar units

Calendar of Month

calendar 指定月日历

Points in Time in Alternate Formats

`datenum`	Convert date and time to serial date number
`now`	Current date and time as serial date number
`clock`	Current date and time as date vector
`date`	Current date as character vector
`today`	(Not recommended; use`datetime("today")`) Current date
`eomdate`	(Not recommended; use`dateshift`) Last date of month

Date and Time Components

Extract Components

`一年`	Year number of input date and time
`quarter`	Quarter number of input date and time
`month`	Month number or name of input date and time
`week`	Week number of input date and time
`day`	Day number or name of input date and time
`weekday`	Day of week
`hour`	Hour component of input date and time
`minute`	Minute component of input date and time
`second`	Seconds component of input date and time
`weeknum`	(Not recommended; use`week`) Week in year

Split into Components

`ymd`	Year, month, and day numbers of datetime
`hms`	Hour, minute, and second numbers of datetime or duration
`datevec`	Convert date and time to vector of components
`split`	Split calendar duration into numeric and duration units
`time`	Convert time of calendar duration to duration
`timeofday`	Elapsed time since midnight for`datetime`arrays

Calculate Differences or Shift Dates

`datetime`Arrays

`between`	Calendar math differences
`caldiff`	Calendar math successive differences
`tzoffset`	Time zone offset from UTC
`dateshift`	Shift date or generate sequence of dates and times

Fixed-Format Arrays

`addtodate`	Modify date number by field
`etime`	Time elapsed between date vectors
`months`	(Not recommended; use`between`) Number of whole months between dates

Query Array Contents

`isbetween`	Determine elements within date and time interval
`isregular`	Determine if input times are regular with respect to time or calendar unit
`isnat`	Determine NaT (Not-a-Time) elements
`isdst`	Determine daylight saving time elements
`isweekend`	确定周末d elements
`isdatetime`	Determine if input is datetime array
`isduration`	Determine if input is duration array
`iscalendarduration`	Determine if input is calendar duration array

Convert to Text

`string`	String array
`char`	Character array
`datestr`	Convert date and time to string format

Excel,POSIX, and Other Date and Time Systems

Conversions

`convertTo`	Convert`datetime`values to numeric representations
`exceltime`	ConvertMATLABdatetime toExceldate number
`posixtime`	ConvertMATLABdatetime toPOSIXtime
`juliandate`	ConvertMATLABdatetime to Julian date
`yyyymmdd`	ConvertMATLABdatetime to YYYYMMDD numeric value
`m2xdate`	(Not recommended; use`exceltime`)MATLABdate toExcelserial date number
`x2mdate`	(Not recommended; use`datetime`)Excelserial date number toMATLABserial date number or`datetime`value

Times inMATLAB

`timezones`	List time zones
`leapseconds`	List all leap seconds supported by`datetime`data type

Backward Compatibility

matlab.datetime.compatibility.convertDatenum Convert inputs todatetimevalues in a backward-compatible way

Topics

Represent Dates and Times in MATLAB
Usedatetimearrays to store date and time information. These arrays support arithmetic, sorting, comparisons, plotting, and formatted display.
Compare Dates and Time
You can perform an element-by-element comparison of values in twodatetimearrays or twodurationarrays using relational operators, such as>and<.
- Date and Time Arithmetic
- Plot Dates and Times
Set Date and Time Display Format
TheFormatproperty ondatetime,duration, andcalendarDurationarrays controls the display of values in each array. You can change the value of this property. Changing theFormatproperty does not change the values in the array, only their display.
Specify Time Zones
When you create a datetime, it is unzoned by default. If you work with datetime values from multiple time zones or need to account for daylight saving time, you might need to specify a time zone.
- 日期和时间转换为朱利安日期或POSIX时间
Share Code and Data Across Locales
Follow these best practices when sharing code that handles dates and time with MATLAB^®users in other locales. Write and read dates from other locals.
Core Functions Supporting Date and Time Arrays
Many functions in MATLAB operate on date and time arrays in much the same way that they operate on other arrays.

Troubleshooting

Carryover in Date Vectors and Strings

If an element falls outside the conventional range, MATLAB adjusts both that date vector element and the previous element.

Converting Date Vector Returns Unexpected Output

Because a date vector is a 1-by-6 vector of numbers,datestrmight interpret your input date vectors as vectors of serial date numbers—or interpret serial date numbers as date vectors—and return unexpected output.