๐Ÿ—“๏ธ

Day of Week Calculator

Find the day of the week for any date in history. Doomsday Algorithm proof, day name origins (Tuesday=Thor, etc.), cultural trivia.

Configuration

Chronological Identity

It's a Wednesday!


Wednesday, February 25, 2026

Day 56 of 365 in 2026. 309 days left in the year.

The 8th Wednesday of 2026 (8 of 52 Wednesdays; 44 left).

Did you know?

Wednesday is 'hump day'โ€”the midpoint of the traditional work week.

Information Hub

Step-by-step Doomsday Algorithm for Wednesday, February 25, 2026:

1. Century Anchor Day

For the 2000s, the century anchor is Saturday (2)

Century anchor d

2. Year components (last two digits 26)

a = โŒŠ26/12โŒ‹ = 2, b = 26 mod 12 = 2, c = โŒŠb/4โŒ‹ = 0

a + b + c

3. Doomsday for the year

(a + b + c + d) mod 7

f = 6 โ†’ Saturday. So 4/4, 6/6, 8/8, 12/12 fall on Saturday in 2026.

4. From nearest doomsday to 2/25

Nearest doomsday in Feb: 2/28. Offset: 25 โˆ’ 28 = -3. (6 + -3 + 7) mod 7 = 3 โ†’ Wednesday.

Day of the Week: History, Math & Meaning

Knowing what day a date falls on connects calendar math to history and linguistics. This tool uses the Doomsday Algorithmโ€”a mental math trick you can learnโ€”and explains where the names Tuesday, Wednesday, and the rest come from.

What This Calculator Does

Instant Weekday Lookup

Pick any date and see its weekday immediately. No buttons to pressโ€”the result updates as you change the date. Shows the full long-form date and a rotating fact about that day.

The Doomsday Rule

The algorithm uses modular arithmetic to find weekdays without a calendar. The Math tab walks through the proof for your date: century anchor, year formula, and offset from the nearest "doomsday" (4/4, 6/6, 8/8, 12/12).

Day & Year Context

Results include day-of-year position (e.g., day 48 of 365) and which occurrence of that weekday it is (e.g., 7th Tuesday of the year). Handy for planning and trivia.

A Week Named by the Stars

Day names trace to the seven "wandering stars" of antiquity: Sun, Moon, and five planets. English blends Norse gods (Tiw, Woden, Thor, Frigg) with Roman Saturn for Saturday. The Day Trivia tab has more.

Day of Week Calculator: Find the Weekday for Any Date in History

Find what day of the week any date falls onโ€”your birthday, July 4, 1776, or any date. Free instant results. Doomsday Algorithm proof, day name origins, day-of-year stats. Runs locally, no sign-up.

How to Use the Day of Week Calculator

Pick a date in the date picker; the result updates as you type. The main output shows the weekday in large type (e.g., "It's a Tuesday!") with the full long-form date below. A "Did you know?" line rotates facts about that day. "Go to Today" jumps back to the current date. No Calculate or Resetโ€”everything updates live.

The Doomsday Algorithm: The Math Behind Weekday Calculation

The Doomsday Rule uses modular arithmetic to find the weekday of any date. Each year has a "Doomsday"โ€”a weekday that easy dates (4/4, 6/6, 8/8, 12/12) fall on. The formula f=(d+a+b+c)โ€Šmodโ€Š7f = (d + a + b + c) \bmod 7 combines the century anchor d (e.g., Tuesday for 2000s) with year terms a = โŒŠyy/12โŒ‹, b = yy mod 12, c = โŒŠb/4โŒ‹. From there, count forward or back from the nearest doomsday. The Math tab shows the full proof for your selected date.

Day-of-Year and Weekday Occurrence Stats

The result card shows where your date sits in the year: day number out of 365 (or 366), days left in the year, and which occurrence of that weekday it is (e.g., the 7th Tuesday of 52). Useful for project milestones, countdowns, and calendar trivia.

Why Tuesday, Wednesday, Thursday? The Origins of Day Names

Most English day names come from the seven "wandering stars" visible in antiquityโ€”the Sun, Moon, and five planets. Sunday and Monday are straightforward. Tuesday through Friday honor Norse gods (Tiw, Woden, Thor, Frigg), mirroring Roman gods (Mars, Mercury, Jupiter, Venus). Saturday kept its Roman nameโ€”Saturn's day. "Thursday" nods to Thor; "Wednesday" to Woden (Odin). The Day Trivia tab goes deeper.

Day of Week Calculator FAQ

? How do I find the day of the week for any date?

Pick any date in the date pickerโ€”the result updates live. You'll see the weekday (e.g., "It's a Tuesday!") and full date. "Go to Today" resets to the current date.

? What is the Doomsday Algorithm?

The Doomsday Rule finds weekdays using modular arithmetic. Each year has a "Doomsday"โ€”a weekday that 4/4, 6/6, 8/8, and 12/12 fall on. The formula f=(d+a+b+c)โ€Šmodโ€Š7f = (d + a + b + c) \bmod 7 uses the century anchor d and year terms a, b, c. The Math tab shows the step-by-step proof for your date.

? Where do Tuesday, Wednesday, Thursday get their names?

Most English day names blend Roman and Norse mythology. Sunday and Monday come from the Sun and Moon. Tuesday through Friday honor Norse gods (Tiw, Woden, Thor, Frigg), mirroring Roman gods (Mars, Mercury, Jupiter, Venus). Saturday kept its Roman nameโ€”Saturn's day.
๐Ÿ•’
Time & Date Reference Note

Informational Use: These tools use standard date/time algorithms and your browserโ€™s timezone data (IANA). Results are intended for general reference and planning only.

Verification Recommended: Time zone rules and daylight saving changes vary by region and year. For critical scheduling, payroll, or legal deadlines, confirm results with official sources.

Local Verification: Always confirm times, dates, and business-day counts with official sources or qualified professionals when stakes are high.

ยฉ 2026 CalcRegistry Reference Last Logic Update: FEB 2026Free Online Utility Tools