Pick a date and the calculator counts the calendar days between today and that date, using your device's local date. A future date shows days left, a past date shows days since. Business days count Monday to Friday and do not remove public holidays. Bookmark the page with a date in the link by using the share button: the date is stored in the address, nothing is sent anywhere.
No. If the date is tomorrow the answer is 1 day. On the day itself it shows 0 days.
Use the ready-made holiday countdown pages or type the date of the holiday above.
See also: Holiday Countdowns · Days Between Dates · Business Days Calculator