dateshift

Shift date or generate sequence of dates and time

Syntax

t2 = dateshift(t,'start',unit)

t2 = dateshift(t,'end',unit)

t2 = dateshift(t,'dayofweek',dow)

t2 = dateshift(___,rule)

Description

t2 = dateshift(t,'start',unit) shifts each value in the datetime array t back to the beginning of the unit of time specified by unit. The output t2 is the same size as t.

t2 = dateshift(t,'end',unit) shifts the values ahead to the end of the unit of time specified by unit. The end of a day, hour, minute, or second is also the beginning of the next one. For example, the end of a day occurs at midnight at the beginning of the next day. The end of a year, quarter, month, or week is midnight at the beginning of the last day of that time period.

t2 = dateshift(t,'dayofweek',dow) returns the next occurrence of the specified day of the week on or after each datetime in array t. If the date in t falls on the specified day of the week, then dateshift returns the same date.

t2 = dateshift(___,rule) shifts each value in array t according to the pattern specified by rule. You can use this syntax with any of the arguments in the previous syntaxes.

Examples

Shift Current Date to End of Current Month

Define the current date.

t = datetime('today')

t = datetime
   24-Aug-2020

Shift the date to the end of the same month.

t2 = dateshift(t,'end','month')

t2 = datetime
   31-Aug-2020

Shift Current Date to Next Month

Define the current date.

t = datetime('today')

t = datetime
   24-Aug-2020

Shift the date to the start of the next month.

t2 = dateshift(t,'start','month','next')

t2 = datetime
   01-Sep-2020

Shift the date to the end of the next month.

t2 = dateshift(t,'end','month','next')

t2 = datetime
   30-Sep-2020

Shift Dates to Specific Day of Week

Shift an array of dates forward to the next Friday.

t = datetime([2014,08,03;2014,04,15])

t = 2x1 datetime
   03-Aug-2014
   15-Apr-2014

t2 = dateshift(t,'dayofweek','Friday')

t2 = 2x1 datetime
   08-Aug-2014
   18-Apr-2014

Shift the array of dates backward to the previous Monday.

t2 = dateshift(t,'dayofweek','Monday','previous')

t2 = 2x1 datetime
   28-Jul-2014
   14-Apr-2014

Determine Future Date

Find the date that falls at the end of the fifth week from today.

t = datetime('today')

t = datetime
   24-Aug-2020

t2 = dateshift(t,'end','week',5)

t2 = datetime
   03-Oct-2020

Create Sequence of Dates Falling on Specific Day of Week

Generate a sequence of dates consisting of the next three occurrences of Friday.

t = datetime('today')

t = datetime
   24-Aug-2020

t2 = dateshift(t,'dayofweek','Friday',1:3)

t2 = 1x3 datetime
   28-Aug-2020   04-Sep-2020   11-Sep-2020

Input Arguments

t — Input date and time

datetime array

Input date and time, specified as a datetime array.

unit — Unit of time

'year' | 'quarter' | 'month' | 'week' | 'day' | 'hour' | 'minute' | 'second'

Unit of time, specified as one of the following values:

• 'year'

• 'quarter'

• 'month'

• 'week'

• 'day'

• 'hour'

• 'minute'

• 'second'

dow — Day of Week

scalar integer | character vector | string scalar

Day of the week, specified as a scalar integer indicating the day of week number, or a character vector or string scalar containing a localized day name.

Example: 'Sunday'

Example: 1

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | char | string

rule — Rule for shifting datetime values

character vector | string scalar | scalar integer | array of integer values

Rule for shifting datetime values, specified as a character vector, string scalar, scalar integer, or an array of integer values. If rule is a character vector or string, it must be one of the following.

Value of rule	Description
'next'	Shift datetime to next unit of time or specified day. (Default rule for day of week.)
'previous'	Shift datetime to previous unit of time or specified day.
'nearest'	Shift datetime to nearest occurrence of unit of time or specified day.
'current'	Shift datetime within the current unit of time, or to the specified day in the current week. (Default rule for unit of time.)

If rule is an integer or an array of integers, then:

• When used with the input argument, unit, 0 corresponds to the start or end of the current unit for each datetime, 1 corresponds to the next unit, -1 corresponds to the previous unit, and so on.

• When used with the input argument, dow, 0 corresponds to the specified day in the current week for each datetime, 1 corresponds to the next occurrence of the specified day, -1 corresponds to the previous occurrence, and so on.

• t and rule must be the same size, or one must be a scalar.

If you specify 'dayofweek' and t contains datetime values that fall on that day of the week, then dateshift treats those datetime values as the next or previous occurrences of the specified day of the week. For example, dateshift(datetime(2015,12,24),'dayofweek','thu',rule) returns a datetime value with a date of December 24, 2015 if rule is 'next', 'previous', 1, or -1, because December 24, 2015 is a Thursday.

Extended Capabilities

Tall Arrays

Calculate with arrays that have more rows than fit in memory.

This function fully supports tall arrays. For more information, see Tall Arrays.

Distributed Arrays

Partition large arrays across the combined memory of your cluster using Parallel Computing Toolbox™.

This function fully supports distributed arrays. For more information, see Run MATLAB Functions with Distributed Arrays (Parallel Computing Toolbox).