Tools Category
Free Date & Time Tools — Calculators and Calendar Converters
Free date and time tools for calculations, countdowns, timezone conversion and calendar conversions.
Date and time calculations come up constantly — project deadlines, travel planning, scheduling and historical research all depend on them. Furthermore, calendar system conversions are essential for international and multicultural contexts.
All tools run locally in your browser. Nothing is sent to any server. Moreover, no account is needed and no data is stored anywhere.
The collection covers four areas — date calculators, time zones and world clock, countdown timers, and calendar system converters. Additionally, use the search box or dropdown to jump directly to any tool.
Date Calculators
Calculate date differences, add or subtract dates and find business days.
Date Arithmetic
Date Difference Calculator
The Date Difference Calculator highlights every addition, deletion and change between two text blocks.
Date Add/ Subtract
Use the Date Add/ Subtract tool for fast, accurate results in your browser. Additionally, no account or download is needed.
Business Days Calculator
The Business Days Calculator counts working days between any two dates, excluding weekends and optional public holidays.
Days Until Calculator
Use the Days Until tool for fast, accurate results in your browser. Additionally, no account or download is needed.
Days Left in a Year
Use the Days Left in a Year tool for fast, accurate results in your browser. Additionally, no account or download is needed.
Workweek Calculator
The Workweek Calculator identifies the workweek number, start and end dates for any date of the year.
Year Progress Percentage
The Year Progress Percentage handles all percentage calculations: percentage of a number, percentage change and reverse
Calendar Tools
Calendar Generator
Use the Calendar tool for fast, accurate results in your browser. Additionally, no account or download is needed.
Calendar Week Number
Use the Calendar Week Number tool for fast, accurate results in your browser. Additionally, no account or download is needed.
Recurring Date Generator
Use the Recurring Date tool for fast, accurate results in your browser. Additionally, no account or download is needed.
454 Calendar
Use the 454 Calendar tool for fast, accurate results in your browser. Additionally, no account or download is needed.
Online Date Format Converter
The Online Date Format Converter converts dates between ISO 8601, US, UK, European and custom formats.
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Time Zones & World Clock
Convert between time zones and view the current time worldwide.
Time Zone Tools
Time Zone Converter
The Time Zone Converter converts a time from any time zone to another instantly.
Time zone Offset Converter
The Time zone Offset Converter converts a time from any time zone to another instantly.
World Clock
Use the World Clock tool for fast, accurate results in your browser. Additionally, no account or download is needed.
Military Time Converter
Use the Military Time tool for fast, accurate results in your browser. Additionally, no account or download is needed.
UNIX Timestamp Converter
The UNIX Timestamp Converter converts Unix timestamps to human-readable dates and vice versa.
Unix Timestamp To Date Converter
The Unix Timestamp To Date Converter converts Unix timestamps to human-readable dates and vice versa.
Milliseconds To Date
Use the Milliseconds To Date tool for fast, accurate results in your browser. Additionally, no account or download is needed.
Excel Serial Date Converter
The Excel Serial Date Converter converts Excel serial date numbers to calendar dates and back.
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Countdown & Timers
Count down to any event or calculate time remaining from now.
Timers & Countdowns
Countdown Timer
The Countdown Timer displays a live countdown in days, hours, minutes and seconds to any future date and time.
Time Until Calculator
Use the Time Until tool for fast, accurate results in your browser. Additionally, no account or download is needed.
Moon Phase Calculator
The Moon Phase Calculator calculates pH, pOH, hydrogen ion concentration and buffer pH using Henderson-Hasselbalch.
Next Leap Year
Use the Next Leap Year tool for fast, accurate results in your browser. Additionally, no account or download is needed.
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Calendar Converters
Convert dates between over 20 historical and regional calendar systems.
Middle Eastern & Islamic
Gregorian To Hijri Date Converter
The Gregorian To Hijri Date Converter converts dates between the Islamic Hijri calendar and the Gregorian calendar in bo
Hijri To Gregorian Date Converter
The Hijri To Gregorian Date Converter converts dates between the Islamic Hijri calendar and the Gregorian calendar in bo
Solar Hijri Shamsi To Gregorian Converter
The Solar Hijri Shamsi To Gregorian Converter generates SHA-256, SHA-512, SHA-1 and SHA-384 hashes for any text input in
Persian Jalali Date Converter
The Persian Jalali Date Converter converts dates between the Persian (Jalali) solar calendar and the Gregorian calendar.
Hebrew Date Converter
The Hebrew Date Converter converts dates between the Hebrew (Jewish) calendar and the Gregorian calendar.
Bahai Calendar Converter
The Bahai Calendar Converter converts dates between the Baha'i (Badí') calendar and the Gregorian calendar.
Asian Calendar Systems
Chinese Lunar Calendar Converter
The Chinese Lunar Calendar Converter converts dates between the Chinese lunar calendar and the Gregorian calendar.
Japanese Era Date Converter
The Japanese Era Date Converter converts dates between the Japanese imperial era system (Reiwa, Heisei, Showa) and the G
Korean Lunar Calendar Converter
The Korean Lunar Calendar Converter converts dates between the Korean lunar calendar and the Gregorian calendar.
Vietnamese Lunar Calendar Converter
The Vietnamese Lunar Calendar Converter converts dates between the Vietnamese lunar calendar and the Gregorian calendar.
Hindu Calendar Vikram Samvat Converter
The Hindu Calendar Vikram Samvat Converter adds or removes tax instantly.
Indian Saka Calendar Converter
The Indian Saka Calendar Converter converts dates between the Indian National Calendar (Saka) and the Gregorian calendar.
Thai Buddhist Calendar Converter
The Thai Buddhist Calendar Converter converts dates between the Thai Buddhist Era (BE) calendar and the Gregorian calendar.
Tamil Calendar Converter
The Tamil Calendar Converter converts dates between the Tamil calendar and the Gregorian calendar.
Bengali Calendar Converter
The Bengali Calendar Converter converts dates between the Bengali calendar and the Gregorian calendar.
Nepali Calendar Date Converter
The Nepali Calendar Date Converter converts dates between the Nepali Bikram Sambat (BS) calendar and the Gregorian (AD) calendar.
Bs To Ad Nepali Date Converter
The Bs To Ad Nepali Date Converter converts dates between the Nepali Bikram Sambat (BS) calendar and the Gregorian (AD) calendar.
Nepali Date Converter Ad To Bs
The Nepali Date Converter Ad To Bs converts dates between the Nepali Bikram Sambat (BS) calendar and the Gregorian (AD) calendar.
Historical & Other Calendars
Julian To Gregorian Date Converter
The Julian To Gregorian Date Converter converts dates between the Julian and Gregorian calendar systems.
Julian Day Number Converter
The Julian Day Number Converter converts Gregorian dates to Julian Day Numbers (JDN) used in astronomy and chronology, a
French Republican Calendar Converter
The French Republican Calendar Converter converts dates between the French Revolutionary calendar and the Gregorian calendar.
Mayan Calendar Converter
The Mayan Calendar Converter converts Gregorian dates to the Mayan Long Count, Tzolk'in and Haab' calendar systems.
Coptic Calendar Converter
The Coptic Calendar Converter converts dates between the Coptic Christian calendar and the Gregorian calendar.
Ethiopian Date Converter
The Ethiopian Date Converter converts dates between the Ethiopian calendar (Ge'ez/Ethiopic) and the Gregorian calendar.
Religious Calendar Hub
The Religious Calendar Hub shows the current date in Islamic, Hebrew, Buddhist and Christian liturgical calendars simultaneously.
World Calendar Converter
The World Calendar Converter converts dates across 20+ calendar systems in a single tool.
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Date & Time Tools for Everyone
Time is one of the most fundamental units in both everyday life and professional work. These tools handle the date and time calculations that come up most frequently. Furthermore, the calendar converters cover over 20 historical and regional calendar systems.
Business day calculators, timezone converters and countdown timers are all available without any account or installation. Moreover, the calendar system tools are particularly useful for researchers, genealogists and international professionals.
All tools run entirely in your browser. Nothing is uploaded and nothing is stored. Additionally, every tool is responsive and works on phones and tablets without any app.