Daily Calendar Calculator

YYYY-MM-DD. Leave blank to start from today.
Only affects the weeks-and-days part. Years and months are always calendar steps.
Resulting date
2026-09-15
Date Add Calculator
Falls on a
Tuesday
Date before any working-day roll
2026-09-15
Days rolled
0 days
Calendar days from the start date
1 days
Working days from the start date
1 days
Day of the year
258
ISO week
2026-W38
ISO week number
38
Start date falls on
Monday
Counted from
2026-09-14
Clamped to the month end
no
Day-counting basis
exclusive (start date is day 0)
Summary
2026-09-14 plus 1 day is 2026-09-15 (Tuesday).
Worked out from ISO 8601-1:2019, Date and time - Representations for information interchange and 4 other sources.

How this is worked out

2 steps
  1. 2026-09-14 + 1 calendar day = 2026-09-15
  2. 2026-09-15 is a Tuesday, day 258 of 2026, in ISO week 2026-W38.

Results are general information, not financial, tax, legal, medical or engineering advice.