sumivo

Day Counter

Count calendar days between two dates with or without both endpoint dates included.

01 / INPUTS

02 / RESULT

INCLUSIVE DAYS

31 days

Including endpoints
31
Between dates
30

Calculation trace

  1. 2026-01-31 − 2026-01-01 = 30 days
    30 days
    Exclusive count
  2. 30 + 1 endpoint day = 31 days
    31 days
    Inclusive count
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SOURCES

  • International Organization for Standardization (ISO)
    ISO 8601 — Date and time format ↗

    Calendar date representation and civil day counting on the proleptic Gregorian calendar

    Accessed 2026-08-19