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Activity period

Three related metrics describing when and how long the activity of a given element (project, team, participant) lasted.

  • Date of first increment: the first recorded activity in the entire history, regardless of the selected date range.
  • Date of last increment: the last recorded activity in the entire history, likewise regardless of the selected date range.
  • Duration: the number of calendar days with activity within the selected date range, counting both boundary days.

Duration counts calendar days, including weekends and holidays. Business days in the same period are shown by a separate metric, Business Days from the Work Dynamics Indexes.

Effect of the selected date range on Duration​

Duration is calculated on the intersection of two periods: the selected date range and the interval between the first and last activity. The start is the later of the two dates (the start of the range or the first activity), and the end is the earlier of the two (the end of the range or the last activity).

This results in several concrete behaviors:

  • A range narrower than the activity history: Duration equals the length of the range. With activity from January to the end of February and a date range from January 15 to 20, Duration is 6 days.
  • A range starting in the middle of the history: Duration is calculated from the start of the range. The same activity from January to the end of February, viewed within a range from January 15 to the end of the year, gives 45 days.
  • A range wider than the activity history: Duration equals the full interval of activity, because days with no activity at all at the ends of the range are not included in the calculation.
  • Activity on a single day: Duration is 1.
  • No activity within the range: Duration is 0, and the dates of first and last increment still show the history from before the range.

The dates of first and last increment show the entire history, so in a single table row you can see, side by side, Date of first increment 2023-01-05, Date of last increment 2025-06-30, and Duration 30, when the date selector is set to the last 30 days. A Date of first increment earlier than the start of the selected range is a signal that Duration describes only a slice of that element's work.

Participant versus project/team

At the participant level, these three metrics describe that person's own activity directly, while at the project or team level, they describe the combined activity of all participants together: Date of first increment is the earliest date among all participants, Date of last increment is the latest, and Duration is calculated between these two extreme dates, bounded by the selected date range. This means that a project's or team's Duration can be longer than the working period of any single participant, if different people were active at different, non-overlapping moments within that date range.

Duration versus continuity of work

These three metrics describe the extreme points in time. A long Duration therefore speaks to the distance between the first and last activity, with no information about how the work was distributed between them. To check whether the activity was continuous or interrupted, Duration has to be set alongside Productive Days and Days Between Increment from the Work Dynamics Indexes. A large difference between Duration and the number of Productive Days points to long breaks in the middle of the period.

When comparing projects or participants with different tenures, set Duration alongside the Date of first increment. A date outside the selected range shows that the person or project in question has work behind them that this column does not cover, and widening the date filter will show its full picture.

See also​