WhenMathBusiness Calendar Availability Heatmap
See every date in a range classified as open or closed, and the exact reason for each closure, under a stated workweek and custom exclusions. The range is half-open, so the start date counts and the end date does not, matching the Workdays in Period Calculator.
Worked example
A five day range from a Monday through the following Saturday, checked against a Monday through Friday workweek with no other exclusions, reports five open days and zero closed days, since every date in that specific half-open range falls on a weekday. Extend the same range by two more days into the following weekend and the heatmap adds two closed days, each one labeled as falling outside the stated workweek rather than lumped together with a holiday or custom exclusion, since those are three genuinely different reasons a date can be closed.
Common mistakes
- Reading the end date as included. It is not, the same half-open convention used throughout WhenMath's business-day tools, so a range ending on a Friday should use the following Saturday as the end date to include that Friday.
- Requesting a range longer than two years, which this tool intentionally rejects to keep the day-by-day enumeration fast and reviewable.
Limitations
This classifies dates using only the workweek and exclusions you enter. It does not apply any specific country's official holiday calendar automatically, and it makes no claim about actual business hours of operation beyond the open or closed classification itself.
Frequently asked questions
- What is the longest range this supports?
- Up to two years in one request, which keeps the generated table a reasonable size to review on a single page.
- Can I see which specific reason closed a given date?
- Yes, each closed date in the table states whether it fell outside the workweek, was a custom exclusion, or matched a selected holiday preset.