How to use the reporting period date range calculator
- Pick the as-of date, which is the last day of every range.
- Choose the month your fiscal year starts in, and the weekday your week starts on.
- Optionally open the advanced options to change the trailing days and months.
- Read the ranges with their start, end and number of days, and the same ranges one year earlier.
Formula
Week to date: from the start of the week to the as-of date
Month, quarter and year to date: from the first day of the month, fiscal quarter or fiscal year
Last N days: from the as-of date - (N - 1) days
Last N months: from the day after the as-of date moved back N months
The prior-year version of a range moves both ends back one year. February 29 becomes February 28.
October 10, 2026 with a calendar year
Week to date starts on Monday, October 5 and runs 6 days. Month to date and quarter to date both start on October 1, because October is the first month of the last quarter. Year to date runs from January 1, 2026 to October 10, 2026, which is 283 days. Last full month is September 1 to September 30. Last 30 days starts on September 11, and last 3 months starts on July 11 and runs 92 days.
With a fiscal year that starts in July, year to date starts on July 1, 2026 and quarter to date starts on October 1. The same year to date one year earlier is January 1, 2025 to October 10, 2025. For an as-of date of February 29, 2028 the matching prior-year range ends on February 28, 2027.
Why ranges need exact dates
Reports that compare this period with the same period a year ago go wrong when the start dates are off by a day, because the number of days in each range differs. Listing the exact start and end of each range, with the day count, makes it easy to check a query or a spreadsheet filter. The prior-year table gives the dates for the comparison.
Last N months is defined here as ending on the as-of date and starting the day after the date N months back, so three months ending October 17 begin on July 18. If your report uses whole calendar months, use Last full month instead.
Fiscal years and calendars
A fiscal year can start in any month, and its quarters are three months from there. Some companies use 4-4-5 or 52-53 week calendars, which do not follow calendar months. For those, see the Fiscal 4-5-4 Calendar Generator, and for quarter dates in a normal fiscal year, the Fiscal Quarter Calendar. The Week Number Calculator gives the week of the year, and the Date Range Chunker splits a range into equal parts.
Assumptions and limits
- Calendar months are used for the fiscal year and quarters. 4-4-5 and 52-53 week calendars are not.
- Weeks start on the weekday you choose and run seven days.
- Every range ends on the as-of date, except last full month.
- The as-of date starts as today, so the results change each day until you set a date.
Frequently asked questions
How is the quarter chosen for a fiscal year?
The fiscal year starts on the first day of the month you pick, and each quarter is three months from there. The quarter containing the as-of date gives the start.
Why do the prior-year ranges have the same dates?
They keep the same calendar dates one year earlier, so the number of days is the same except around February 29.
What does Last 30 days include?
It includes the as-of date and the 29 days before it, which is 30 days in all.
Can the week start on Saturday?
This tool offers Monday and Sunday. Those are the two choices most reports use.