How Planning Calculates Working Time and Dates

Planning follows certain guidelines when it calculates working times and dates.

Weekdays are working days. Weekend days are non-working days. Vision calculates a working day as equal to 8 (eight) hours. Holidays are accounted for depending on settings configured on the Holiday Calendar.

Dates and durations for elements at higher levels of the Work Breakdown Structure (WBS) are not calculated by adding up durations at lower levels.

Instead, the dates of an element at a higher WBS level are determined as follows:

  • Its start date is equal to the earliest start date/time of all its children.

  • Its end date is equal to the latest end date/time of all its children.

For example, if a project for building a house has a phase with six tasks:

  • The start date of the first task is June 1, which becomes the phase start date.

  • The end date of the sixth task is September 30, which becomes the phase finish date.

If you move a WBS element forward or backward in time, you must double-check that its duration and its resource assignments still make sense.