Booking Window Calculator

How to use this calculator

Choose the provider's rule, lead time and release time zone. For monthly batches, enter the arrival-window starting day and release day. Add one or more desired arrival dates.

Monthly batch assignment happens before subtracting lead months. A window beginning on the 15th covers the 15th through the 14th of the next month. Missing release dates follow your clamp or reject choice. Exported reminders are timed one-minute events at the release instant.

A worked example

An arrival window beginning May 15 and ending June 14, with a four-month lead and release day 15, opens January 15. June 15 belongs to the next batch and opens February 15.

Are reservation rules loaded automatically for a park or hotel?

No. Enter the current provider rule, including its time zone and exceptions. Facilities can have different release windows, and provider terms can change.

Further reading: Source workflow and conventions. Your entered rules determine this result.

Which calendar and years are supported?

Use Gregorian dates from 1900 through 2100, with results inside that range. Most daily plans are limited to 366 dates; academic terms and sprint plans allow up to 731. Forms limit the number of entries to keep calculations responsive. Holidays and policy rules come from your inputs. Date-only plans ignore DST; tools with time-zone inputs use the browser's time-zone data and explicitly resolve repeated times. Calendar exports preserve date-only markers or exact timed events as appropriate. Calculations run only when requested, without background polling.

What happens to my dates?

Calculations run on your device. Saving a calculation is optional and keeps it in this browser. A setup link contains the dates and settings you entered; anyone with the link can read them. Use one tab per saved calculator. Clear saved data from Privacy & settings.