Deadline Calculator

Add or subtract days from a start date, then correct the result for weekends and holidays if needed.

This is useful for filing dates, project milestones, due dates, and other time-sensitive planning.

Result

--

Run the calculation to see the deadline.

MetricValue
Raw deadline--
Corrected deadline--
Weekday--
US holiday--

Quick Answer

The calculator adds or subtracts a day count from a start date and can move the result off weekends or holidays.

How to Calculate

  1. Choose the start date.
  2. Enter the number of days.
  3. Choose whether the deadline is after or before the start date.
  4. Select a correction rule and click Calculate.

Formula

After = start date + days

Before = start date - days

Weekend and holiday correction moves the result to the nearest business day in the chosen direction.

Worked Examples

Example 1: A 30-day deadline after March 29 lands on April 28 before corrections.

Example 2: A deadline on Saturday can move to Monday with weekend correction.

Example 3: A filing date near Christmas may shift forward to the next business day if holiday correction is enabled.

How to Interpret Your Results

OutputMeaningAction
Raw deadlineThe unadjusted date after adding or subtracting days.Use it as the base result.
Corrected deadlineThe business-day adjusted date.Use it when weekends or holidays matter.
No changeThe raw date already meets the rule.No further adjustment is needed.

Frequently Asked Questions

If weekend correction is enabled, the deadline moves to Monday when counting forward and to Friday when counting backward.

The calculator uses common US federal holidays. State-specific rules can vary, so check local requirements.

Yes. Use the before option to subtract days from the start date.

Related Calculators

References

  • OmniCalculator reference page
  • The calculator uses date addition and subtraction with optional business-day corrections.
  • Last reviewed: March 2026.