AscendLab

Time tools

日期加减计算

Free browser tool

Date Add Calculator for Days, Weeks & Business Days

Add or subtract days, weeks, months, years, or business days from a start date in your browser.

Date inputs
Add or subtract days, weeks, months, or years from a date.
Calculated date
Negative amounts subtract from the start date.

Result

2026-06-20

Sunday, June 21, 2026

Quick answer

Add a positive amount to move forward in time, or a negative amount to move backward.

Business day mode skips weekends for day-based offsets.

Best inputs

Use exact start dates

Pick the calendar date that should count as the baseline.

Choose the right unit

Use days for precise offsets, weeks for schedule blocks, and months or years for calendar planning.

Date offset method
The calculator applies the chosen unit to a local date.
Days and weeks move by exact day counts.
Months and years use calendar month and year behavior.
Business day mode skips Saturday and Sunday for day offsets.
Example, Assumption, and Limitation
Use the result as a practical estimate or transformation, then confirm edge cases for critical work.

Example

Adding 30 days to May 22, 2026 gives June 21, 2026.

Assumption

Business day mode excludes weekends only.

Limitation

Public holidays, local legal rules, and cutoff times are not included.

Common use cases
These pages are built for lightweight browser-side work, examples, and planning.

Project deadlines

Find dates after fixed day offsets.

Billing cycles

Add months or years to renewal dates.

Scheduling

Move forward by workday counts.

Content calendars

Plan publish dates from a start date.

Frequently asked questions

Can I subtract days from a date?

Yes. Enter a negative amount to subtract days, weeks, months, or years.

What does business days mode do?

Business days mode skips Saturdays and Sundays when the selected unit is days.

Does it account for holidays?

No. This page skips weekends only; use a holiday-aware workflow for payroll or legal deadlines.

Does the calculation run locally?

Yes. The date calculation runs in your browser.

Suggested workflow

Date planning workflow

Add offsets, count business days, then calculate detailed differences.