What the countdown measures
The count is the gap between today and a target date, expressed as a plain total of days and broken down into years, months, weeks and days. The only choice that changes the total is whether the target day itself is counted.
- Total days — the raw span, weekends and holidays included.
- Include the end date — on means "through" the target and adds one day; off means "up to" it.
- Breakdown — the same span shown as years, months and weeks for readability.
Calendar days stretch further as business days
Counting only weekdays skips every Saturday and Sunday, so a target that is a fixed number of business days out sits much later on the calendar — roughly seven calendar days for every five business days.
Ninety business days reaches about 36 calendar days further than ninety calendar days, since only five days in seven are counted.
Two things people get wrong
- Days are not months. A count stated in days is exact; three calendar months can be anywhere from 89 to 92 days. When a deadline is written in days, count days.
- Boundary counting. "How many days from Monday to Friday" is 4 or 5 depending on whether the last day is included — the include-end-date toggle is what settles it.
Common questions
How is the number of days counted?
Subtract the start date from the target date. Whether the final day itself counts depends on the include-end-date setting: turning it on adds one, which matters when a deadline is stated as "on or before" a date.
What is the difference between calendar days and business days?
Calendar days count everything. Business days count only Monday to Friday, so the same target date lands far fewer working days away. Public holidays are not removed unless you account for them separately.
Does the countdown handle leap years?
Yes. February 29 is included automatically for any year divisible by 4, except century years not divisible by 400. Without that rule, long spans would drift by a day every few years.
