String to calendar date
cal = CL_dat_str2cal(str)
Decodes a string into a calendar date.
The input format must have the form: "year / month / day [hours : minutes : seconds]"
The calendar date is a column vector [year;month;day;hours,minutes;seconds].
Note:
%nan is returned if the input string format is not correct.
Formatted calendar date (1xN)
Calendar date (6xN)
CNES - DCT/SB