Bug: Possible TIMEDIFF error in Spreadsheet Plugin

TIMEDIFF gives false result if mixed with MAX/MIN of the dates

Test case

A table calculating workload distribution between months is built according to the following idea:

           Jan      Feb       Mar    Days in Jan   Days in Feb   Days in Mar
--------X--------X--------X--------X-------------X-------------X-------------X
Task 1        -----------------      (calculate)   (calculate)   (calculate)
Task 2              -----            (calculate)   (calculate)   (calculate)
Etc.     (Gantt)
--------X--------X--------X--------X-------------X-------------X-------------X

Above calculation is performed using rather long formula giving the set intersection of the worktime interval and full-month interval, i.e. TIMEDIFF(MAX(1 Jan, begin of task), MIN(31 Jan, end of task)) for January etc. Before this calculus, the codition is necessary throwing off the cases of work intervals not intersecting with particular full-month interval.

The resulting table looks as follows:

Second row is for calibration: defining the end of particular month. The next day after the end of month is used in order to secure consistency with TIMEADD result.

You can see the error in Days in October if October is not last month. The difference is exactly 23 hours.

If the last day of month is used in the calibration, the error occurs in November.

Note: "nie" is Polish "no", indicating that there are no days of particular task in particular month.

Environment

-- AndrzejGoralczyk - 16 Sep 2004

Follow up

Fix record