datenum (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