Date Calculator

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Days Between Dates

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Due Date Calculator

Calculate Days Between Two Dates

Start Date

End Date

Include end day (add 1 day)

29 days between dates

Years: 0

Months: 0

Weeks: 4

Days: 29

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Start Date

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Years

Months

Weeks

Days

Result: September 7, 2025

Due Date Calculator

Estimate Based On

First Day of Last Period

Average Length of Cycles

Estimated Due Date: April 16, 2026

First Trimester End: October 16, 2025

Second Trimester End: January 22, 2026

Weeks Pregnant: 8 weeks

About Date Calculations

Gregorian Calendar

The Gregorian calendar is the most widely used calendar today. It was introduced in 1582 by Pope Gregory XIII to correct inaccuracies in the Julian calendar.

A standard year has 365 days, with a leap year of 366 days. The months have varying lengths: April, June, September, and November have 30 days; February has 28 days (29 in leap years); and the rest have 31 days.

Pregnancy Calculations

Due date calculation typically uses Naegele's rule: first day of last menstrual period + 7 days + 1 year - 3 months.

Pregnancy is divided into three trimesters, each approximately 13 weeks. The due date is an estimate, and only about 5% of babies are born on their exact due date.