
The below is only applicable with enabled date rollup. To learn more: https://help.easyprojects.net/hc/en-us/articles/7385235334157-Date-Rollup
Should you specify no end date, duration, progress or estimated hours for an activity that has one or more sub-ones, Easy Projects will do it for you. The rules that govern the way an activity’s end date, progress, etc. are calculated are as follows:

Parameter | Calculation Rule | Notes |
Start Date |
|
For an activity with one or more sub-activities, ‘Start Date’ is a required field. |
End Date |
|
Only top level sub-activities, that is, immediately below the parent activity hierarchically, are taken into account in the calculations. |
Duration | This value is calculated as the difference between End Date and Start Date | Expressed in days and hours. Minimum non-zero duration is 0.25 hours (15 minutes). Refer to Activity details to learn more. |
Progress | Parent activity’s progress is calculated as a weighted mean of its sub-activities’ completion rates, or ![]() |
Only top level sub-activities are taken into account in the calculations. |
Estimated Hours | These are calculated as a total of estimated hours of all sub-activities the parent activity has. | Only top level sub-activities are taken into account in the calculations. |
Changing parent activity’s start date

Example:
A parent activity had May 03, 2005 as its start date, and had a sub-activity starting on May 10, 2003. Subsequently, the parent activity’s start date was rescheduled to May 1, 2005. As a result the sub-activity’s start date would be recalculated 2 days back, to become May 8, 2006. The sub-activity’s end date, if specified, would move back the same number of days.
Adding a sub-activity with a start date to an activity without

Activity dependency effects

Public holidays
When a public holiday falls between the start and end dates it is treated as a day off and affects the duration of the activity just like weekends do when 'Treat weekends as workdays' is turned off (see Company Schedule).
Accordingly, if you set a start date and a duration the end date will be calculated taking into account the public holidays and weekends.
Personal schedule & Resource loading
When a personal vacation falls between the start and end date of an activity, it has consequences for your work load. Easy Projects will subtract the off hours according to your personal schedule from your total available hours.
Examples below discuss additional details.
Example:
Case 1. Fred and Mike are assigned to a task that lasts from Monday to Friday (full work week) and it has 80 estimated hours, thus each is assigned half the amount of work. Both have regular personal schedule (eight hours a day, Mon to Fri work week).
With such baseline conditions, the users' work load while working on the task will be as follows:
Fred — available hours: 40, personal estimated hours: 40, personal loading: 8 hours/day Mon to Fri
Mike — available hours: 40, personal estimated hours: 40, personal loading: 8 hours/day Mon to Fri
Case 2. Fred has been allowed 2 paid days off on Wednesday and Thursday in the middle of the task. As a result the work load picture will become as follows:
Fred — available hours: 24, personal estimated hours: 40, personal loading: 13.33 hours/day Mon, Tue, Fri (overloading)
Mike — available hours: 40, personal estimated hours: 40, personal loading: 8 hours/day Mon to Fri.
You can view the work load status by generating a resources report with the 'Resource Loading Report' radio button selected, as shown in the picture below where:
- Red squares denote work days with overloading (over 100% work hour allocation). The number of hours allocated for the day are indicated (10 in this case).
- Black squares mark days off, in this case Regular vacation type (see Vacation Calendar for details)
- Rose squares mark 'allocated' work days with 80.00 to 100.00% allocation. The number of hours allocated for the day are indicated (6 in this case).