Financial Toolbox

datenum

Create date number

Syntax

• DateNumber = datenum(DateString)
  DateNumber = datenum(DateString, Pivot)
  DateNumber = datenum(Year, Month, Day)
  DateNumber = datenum(Year, Month, Day, Hour, Minute, Second)
  

Description

DateNumber = datenum(DateString) returns a serial date number given a date string. Date numbers are the number of days that has passed since a base date. In MATLAB, date number 1 is January 1, 0000 A.D. If the input includes time components, the date number includes a fractional component. If the input is only a time component, the date number is only a fractional time component.

The date string can be any of several forms.

• '19-may-1999'
  'may 19, 1999'
  '19-may-99'
  '19-may' (current year assumed)
  '5/19/99'
  '5/19' (current year assumed)
  '19-may-1999, 18:37'
  '19-may-1999, 6:37 pm'
  '5/19/99/18:37'
  '5/19/99/6:37 pm'
  '18:37'
  

Unless you specify a pivot year, date strings with two-character years, e.g., 12-june-12, are assumed to lie within the 100-year period centered about the current year.

DateNumber = datenum(DateString, Pivot) assumes that two-character years lie within the 100-year period beginning with the pivot year. The default pivot year is the current year minus 50 years.

DateNumber = datenum(Year, Month, Day) returns a serial date number given year, month, and day integers.

DateNumber = datenum(Year, Month, Day, Hour, Minute, Second) returns a serial date number given year, month, day, hour, minute, and second integers.

Note    This function now ships with basic MATLAB. It originally shipped only with the Financial Toolbox. This description remains here for your convenience.

Examples

• DateNumber = datenum('19-may-1999')
  DateNumber = 730259
  
  DateNumber = datenum('5/19/99')
  DateNumber = 730259
  
  DateNumber = datenum('19-may-1999, 6:37 pm')
  DateNumber = 730259.78
  
  DateNumber = datenum('5/19/99/18:37')
  DateNumber = 730259.78
  
  DateNumber = datenum('6:37 pm')
  DateNumber = 0.78
  
  DateNumber = datenum(1999, 5, 19)
  DateNumber = 730259
  
  DateNumber = datenum(1999, 1:6, 19)
  DateNumber = [730139  730170  730198  730229  730259  730290]
  
  DateNumber = datenum(1999, 5, 19, 18, 37, 0)
  DateNumber = 730259.78
  
  DateNumber = datenum(730259)
  DateNumber = 730259
  

The next example demonstrates the use of the pivot year in interpreting date strings with two-character years.

• DateNumber = datenum('12-june-12')
  DateNumber = 
          735032 
  datestr(735032)
  ans =
  12-Jun-2012
  
  DateNumber = datenum('12-june-12',1900)
  DateNumber = 
          698507
  datestr(698507)
  ans =
  12-Jun-1912
  

See Also

datedisp, datestr, datevec, daysact, now, today

datemnth

datestr