Day of the Week कैलकुलेटर — मुफ़्त ऑनलाइन टूल और फॉर्मूला
Mathematical calendar algorithm resolving the exact weekday name, ISO week number, and ordinal day of the year for any date in history.
Computes the exact weekday using Christian Zeller's modular congruence. Valid for any date from 1582 onwards across the entire Gregorian calendar.
फॉर्मूला और गणना की विधि
Implements Christian Zeller's 1882 mathematical congruence algorithm. By re-indexing January and February as months 13 and 14 of the preceding year, the equation produces an exact modulo-7 integer mapped deterministically to Saturday (0), Sunday (1), Monday (2), through Friday (6).
वेरिएबल परिभाषाएँ और माप इकाइयाँ
Historical Weekday Derivation (July 20, 1969 - Apollo 11 Moon Landing)
Determine the exact day of the week for the historic Apollo 11 lunar landing on July 20, 1969:
Zeller's Congruence and the ISO-8601 Calendar Standard
Before modern computing, determining weekdays for historical archives, probate wills, and genealogical records required complex perpetual calendar tables. Christian Zeller's congruence solved this through integer arithmetic, elegantly overcoming the irregular cadence of months by shifting the calendar year's beginning to March 1st.
Under the international ISO-8601 standard, Monday is formally designated as day 1, and the first week of the year is defined as the week containing the first Thursday of January.
Day of the Week कैलकुलेटर से जुड़े अक्सर पूछे जाने वाले प्रश्न
How can I find out what day of the week I was born on?
Simply select your birth date in the calendar widget. The calculator will instantly reveal the exact day of the week (Monday through Sunday) along with historical ordinal statistics.
What is an ISO week number?
An ISO week number represents the standardized week index (1 to 52 or 53) according to ISO-8601. Each week starts on Monday, and Week 1 is the week that contains the first Thursday of the year.
How do you calculate the day of the year (ordinal date)?
The day of the year is the cumulative sum of days in all preceding months of that year plus the current day of the month (e.g., February 1 is day 32; December 31 is day 365, or 366 in a leap year).
Does this work for dates far in the future or past?
Yes. The mathematical congruence is valid for any Gregorian calendar date from October 15, 1582 onwards into the indefinite future.
संबंधित ऑनलाइन कैलकुलेटर
Day of the Week कैलकुलेटर के साथ अक्सर संदर्भित अन्य कैलकुलेटर।
Date Difference कैलकुलेटर
Exact chronological elapsed duration model calculating absolute calendar days, full weeks, months, years, and total hours between two dates.
उम्र कैलकुलेटर
अपनी जन्म तिथि (Date of Birth) दर्ज करें और आज की तारीख तक अपनी वास्तविक उम्र, कुल महीने, सप्ताह, दिन, घंटे और अगले जन्मदिन की उल्टी गिनती तुरंत देखें।
Date Add & Subtract कैलकुलेटर
Calendar offset projection engine adding or subtracting discrete years, months, weeks, and days to determine future or past target dates.