Represent Dates and Times in MATLAB
The primary way to store date and time information is in
which support arithmetic, sorting, comparisons, plotting, and formatted
display. The results of arithmetic differences are returned in
or, when you use calendar-based functions, in
For example, create a MATLAB® datetime array that represents two dates: June 28, 2014 at 6 a.m. and June 28, 2014 at 7 a.m. Specify numeric values for the year, month, day, hour, minute, and second components for the datetime.
t = datetime(2014,6,28,6:7,0,0)
t = 28-Jun-2014 06:00:00 28-Jun-2014 07:00:00
Change the value of a date or time component by assigning new
values to the properties of the datetime array. For example, change
the day number of each datetime by assigning new values to the
t.Day = 27:28
t = 27-Jun-2014 06:00:00 28-Jun-2014 07:00:00
Change the display format of the array by changing its
The following format does not display any time components. However,
the values in the datetime array do not change.
t.Format = 'MMM dd, yyyy'
t = Jun 27, 2014 Jun 28, 2014
If you subtract one
datetime array from another,
the result is a
duration array in units of fixed
t2 = datetime(2014,6,29,6,30,45)
t2 = 29-Jun-2014 06:30:45
d = t2 - t
d = 48:30:45 23:30:45
By default, a
duration array displays in
the format, hours:minutes:seconds. Change the display format of the
duration by changing its
Format property. You can
display the duration value with a single unit, such as hours.
d.Format = 'h'
d = 48.512 hrs 23.512 hrs
You can create a duration in a single unit using the
years functions. For example, create a duration
of 2 days, where each day is exactly 24 hours.
d = days(2)
d = 2 days
You can create a calendar duration in a single unit of variable length. For example, one month can be 28, 29, 30, or 31 days long. Specify a calendar duration of 2 months.
L = calmonths(2)
L = 2mo
calyears functions to specify calendar durations
in other units.
Add a number of calendar months and calendar days. The number of days remains separate from the number of months because the number of days in a month is not fixed, and cannot be determined until you add the calendar duration to a specific datetime.
L = calmonths(2) + caldays(35)
L = 2mo 35d
Add calendar durations to a datetime to compute a new date.
t2 = t + calmonths(2) + caldays(35)
t2 = Oct 01, 2014 Oct 02, 2014
t2 is also a
Name Size Bytes Class Attributes t2 1x2 161 datetime
In summary, there are several ways to represent dates and times, and MATLAB has a data type for each approach:
Represent a point in time, using the
Example: Wednesday, June 18, 2014 10:00:00
Represent a length of time, or a duration in units of fixed length, using the
durationdata type. When using the
durationdata type, 1 day is always equal to 24 hours, and 1 year is always equal to 365.2425 days.
Example: 72 hours and 10 minutes
Represent a length of time, or a duration in units of variable length, using the
Example: 1 month, which can be 28, 29, 30, or 31 days long.
calendarDurationdata type also accounts for daylight saving time changes and leap years, so that 1 day might be more or less than 24 hours, and 1 year can have 365 or 366 days.