Why are some spreadsheet cells gray?

Spreadsheet cells are gray/uneditable when any of the following are true:

The activity associated with the assignment has a duration type of Fixed Units or Fixed Units/Time (you can only manually enter future period values for activities with a duration type of Fixed Duration & Units and Fixed Duration & Units/Time).
The resource or role assigned to the activity does not have any valid worktime for the timeperiod. For resource assignments to task-dependent activities, and for all role assignments to activities, the module determines if there is valid worktime based on the activity calendar. For resource assignments to resource-dependent activities, the module determines if there is valid worktime based on the resource calendar.
The displayed timescale unit in the spreadsheet is smaller than the minimum timescale unit used for time-distributed resource calculations. You can change this setting in the 'Interval for time-distributed resource calculations' field (User Preferences, Resource Analysis tab). For example, if this option is set to Week, you can only enter or edit data in weekly, monthly, or quarterly timescale buckets.
The date of the timescale unit is prior to the Project Planned Start date (for the Budgeted or Planned Units field) or the Remaining Early Start date (for the Remaining Units field) of the activity.
The activity associated with the assignment has an Actual Finish date.
The timescale is set to Day/Shift or Day/Hour.
The timescale is set to display only ordinal dates. You must display primary dates (with or without ordinal dates) to edit future period buckets.
When the timescale is set to display financial period intervals, no financial period is defined for the timeperiod.
You choose to display time-distributed Remaining Early units and costs according to forecast dates rather than remaining early dates in the User Preferences, Resource Analysis tab. This only applies to the Remaining Units field.
You choose to calculate average values for the spreadsheet in the Spreadsheet Options dialog box.
You have not been assigned the Edit Future Periods project privilege.
In the Resource Usage Spreadsheet of the Activities window, you are displaying assignment data for all projects rather than for open projects only. If you are displaying data for all projects, the title of the Display Options bar in the Resource Usage Spreadsheet is "Display: All Projects." To display data for open projects only, click the Display Options bar, then choose Show All Projects to remove the checkmark; the title of the Display Options bar changes to "Display: Open Projects Only."

Last Published Tuesday, January 20, 2026