DATESTR2NUM - Fast conversion of DATESTR to DATENUM
The builtin DATENUM command is very powerful, but if the input is known to be valid and formatted exactly, a specific MEX can be much faster:
For single strings DateStr2Num is about 120 times faster than DATENUM, for a {1 x 10000} cell string, the speed up factor is 300 to 600(!), (Matlab 2011b/64, MSVC 2008).
D = DateStr2Num(S, F)
INPUT:
S: String or cell string in DATESTR(F) format.
In opposite to DATENUM the validity of the input string is *not* checked.
F: Integer number defining the input format. Accepted:
0: 'dd-mmm-yyyy HH:MM:SS' 01-Mar-2000 15:45:17
1: 'dd-mmm-yyyy' 01-Mar-2000
29: 'yyyy-mm-dd' 2000-03-01
30: 'yyyymmddTHHMMSS' 20000301T154517
31: 'yyyy-mm-dd HH:MM:SS' 2000-03-01 15:45:17
230: 'mm/dd/yyyyHH:MM:SS' 12/24/201515:45:17
231: 'mm/dd/yyyy HH:MM:SS' 12/24/2015 15:45:17
240: 'dd/mm/yyyyHH:MM:SS' 24/12/201515:45:17
241: 'dd/mm/yyyy HH:MM:SS' 24/12/2015 15:45:17
1000: 'dd-mmm-yyyy HH:MM:SS.FFF' 01-Mar-2000 15:45:17.123
1030: 'yyyymmddTHHMMSS.FFF' 20000301T154517.123
OUTPUT:
D: Serial date number.
EXAMPLE:
C = {'2010-06-29 21:59:13', '2010-06-29 21:59:13'};
D = DateStr2Num(C, 31)
>> [734318.916122685, 734318.916122685]
Equivalent Matlab command:
D = datenum(C, 'yyyy-mm-dd HH:MM:SS')
The C-file must be compiled before using. This is done automatically at the first call of this function.
Pre-compiled Mex files can be downloaded from: http://www.n-simon.de/mex

Tested: Matlab 6.5, 7.7, 7.8, 7.13, 32/64bit, WinXP/7
Compiler: LCC 2.4/3.8, BCC 5.5, Open Watcom 1.8, MSVC 2008
Compatibility to MacOS, Linux, 64 bit is assumed, but not tested.

See also: DateConvert (Jan Simon)
http://www.mathworks.com/matlabcentral/fileexchange/25594