Month-end clamping
January 31, 2023 plus one month becomes February 28, 2023.
Add or subtract calendar time, find exact and elapsed differences between dates, or count Monday-to-Friday business days.
Calendar arithmetic applies years first, then months, clamping after each step if the current day does not exist in the destination month. Weeks and days are then applied as exact date-only intervals.
Date differences separate complete calendar years and months from remaining days. Business-day mode counts Monday through Friday; public holidays are not currently excluded.
Years and months use calendar clamping; weeks and days use exact date-only intervals.
result = start ± years ± months ± (weeks × 7 + days)Total elapsed days are calculated separately.
difference = complete years + complete months + remaining daysWeekend dates and excluded endpoints are removed; public holidays are not included in the rules.
business days = included Monday–Friday datesJanuary 31, 2023 plus one month becomes February 28, 2023.
February 28 to March 1, 2024 spans two total days.
Monday through Sunday with both endpoints included contains five business days and two weekend days.
Gregorian leap-year rules determine whether February contains 28 or 29 days.
In business-day mode, the start and end switches determine whether each endpoint participates in the count.
Choose Add or Subtract, enter the number of months, and calculate. CalcRocket moves by calendar months rather than treating every month as a fixed number of days.
The day is clamped to the final valid day of the destination month. For example, January 31 plus one month becomes February 28, or February 29 in a leap year.
The calculator follows Gregorian leap-year rules and uses the actual number of days in every month and year.
Date difference measures elapsed days with the start included and end excluded for weekday totals. Business-day mode lets you independently include or exclude either endpoint.
No. This initial version defines business days as Monday through Friday only and does not remove country-specific public holidays.
Calendar months contain 28, 29, 30, or 31 days. That is why calendar addition and exact calendar differences cannot use a single fixed month length.
The calendar result follows year and month boundaries. Total days is the actual count of UTC date-only midnights between the selected dates.