QlikView stores each date, time and time stamp found in data as a date serial number. The date serial number is used for dates, times and time stamps and in arithmetic calculations based on date and time entities. Dates and times can thus be added and subtracted, intervals can be compared, etc. The date serial number is the (real valued) number of days passed since Dec 30, 1899, i.e. the QlikView format is identical to the 1900 date system used by Microsoft Excel for Windows, Lotus 1-2-3, Corel Quattro Pro and other programs, in the range between March 1, 1900 and Feb 28, 2100. For example, 33857 corresponds to Sept 10, 1992. Outside this range, QlikView uses the same date system extended to the Gregorian calendar, which is now the standard calendar in the Western World. The serial number for times is a number between 0 and 1. The serial number 0.00000 corresponds to 00:00:00, whereas 0.99999 corresponds to 23:59:59. Mixed numbers indicate the date and time: the serial number 2.5 represents January 1, 1900 at 12:00 noon. The data is however displayed according to the format of the string. By default, the settings made in the Control Panel are used. It is also possible to set the format of the data by using the number interpretation variables in the script (see Number Interpretation Variables (page 366)) or with the help of a formatting function, see Formatting Functions (page 370). Finally it is also possible to reformat the data in the properties sheet of the sheet object.
Examples:
1997-08-06 is stored as 35648
09:00 is stored as 0.375
1997-08-06 09:00 is stored as 35648.375 or vice versa
35648 with number format 'D/M/YY' is shown as 6/8/97
0.375 with number format 'hh.mm' is shown as 09.00
As mentioned earlier, QlikView will follow a set of rules to try to interpret dates, times and other data types. The final result however will be affected by a number of factors as described above.
