Can a blackout date fall on a weekend?

Yes, it is simply redundant with the weekend exclusion already in effect, and it will not change the result either way.

What happens if a blackout date falls outside the plan's date range entirely?

It has no effect on the result, since a date the plan never reaches cannot push the finish date out any further than it already would be.

Blackout-Date Deadline Planner

Add your own unavailable date blocks on top of the working-day calendar, then see how much they push a deadline out.

Working around a public-holiday preset instead of your own dates? See Holiday Impact Calculator.

Want to learn more?

Worked example

A 3-business-day plan from Monday, January 4, 2027, would normally finish Thursday, January 7, with no exclusions in effect. Add Wednesday, January 6, as a blackout date, a facility closure say, and the finish pushes out to Friday, January 8, since the blackout day is skipped entirely and the plan simply continues counting past it.

Common mistakes

Entering the same blackout date twice, expecting it to count double. It is still just one non-working day, and duplicates are shown but never double-counted toward the delay.
Assuming a public-holiday preset is applied automatically. Blackout dates entered here are entirely manual, not a regional holiday calendar.

Limitations

Blackout dates entered here are not a public-holiday preset. Combine this with the country selector on the Holiday Impact Calculator separately if real regional holidays also need to be accounted for.

Frequently asked questions

Can a blackout date fall on a weekend?: Yes, it is simply redundant with the weekend exclusion already in effect, and it will not change the result either way.
What happens if a blackout date falls outside the plan's date range entirely?: It has no effect on the result, since a date the plan never reaches cannot push the finish date out any further than it already would be.