Precision Date & Time Calculators
Free, fast, and highly accurate tools verified by calendar mathematics experts. Calculate intervals, format conversions, and time zones instantly.
All Free Date & Time Calculators
Choose from our specialized tools for age, timezone conversion, weekday calculation, business days, unix epoch timestamps, and more.
Days Between Dates
Free online days between dates. days between two dates, date difference calculator
Date Calculator
Add or subtract days, weeks, months, or years to any date.
Days From Now
Free online days from now. 30 days from now, 90 days from now, what date is X days from now
Days Ago Calculator
Free online days ago calculator. 30 days ago, what was the date X days ago, date X days in past
Date Duration
Free online date duration. date duration calculator, time between dates years months days
Date Interval
Free online date interval. recurring date calculator, date interval, repeat every N days
Date Formatter
Free online date formatter. date format converter, MM/DD/YYYY to text, date formatter online
Day of Week Calculator
Free online day of week calculator. what day of the week is [date], day of week calculator for any date
Time Calculator
Free online time calculator. time calculator, add subtract time hours minutes seconds
Add Time
Free online add time. add time calculator, time addition, add hours and minutes together
Subtract Time
Free online subtract time. subtract time calculator, time subtraction, minus hours minutes
Time Duration
Free online time duration. time duration calculator, elapsed time HH:MM:SS between two times
Hours Calculator
Free online hours calculator. hours calculator, how many hours between two times of day
Time From Now
Free online time from now. what time will it be in X hours, time from now calculator
Time Ago Calculator
Free online time ago calculator. what time was X hours ago, time ago calculator online
Multiply / Divide Time
Free online multiply / divide time. multiply time calculator, divide time by a number, time math
Age Calculator
Calculate your exact age in years, months, and days from your birthday.
Birthday Calculator
Free online birthday calculator. birthday calculator, next birthday countdown, days until birthday
Age in Days
Free online age in days. how many days old am I, age in days calculator, days since born
Birth Year Calculator
Free online birth year calculator. if I am X years old what year was I born, birth year from age
Zodiac Calculator
Free online zodiac calculator. zodiac sign calculator, what is my star sign, astrology by birthday
Retirement Date
Free online retirement date. when will I retire, retirement date calculator by birth year and age
Business Days Calculator
Count the number of working days between two dates, excluding weekends.
Add Business Days
Free online add business days. add business days to date, X business days from today date
Work Hours Calculator
Free online work hours calculator. work hours calculator, timesheet calculator, clock in clock out
Deadline Calculator
Free online deadline calculator. deadline calculator, project due date, task deadline from today
Payday Calculator
Free online payday calculator. how many days until payday, payday calculator, next pay date
Shift Hours Calculator
Free online shift hours calculator. shift hours calculator, night shift hours, rotating shift schedule
Time Zone Converter
Convert time between any two timezones worldwide instantly.
World Clock
Free online world clock. world clock, current time in cities worldwide, time around world
Meeting Time Planner
Free online meeting time planner. best time for meeting across time zones, remote meeting scheduler
UTC Converter
Free online utc converter. UTC time converter, UTC to local time, UTC offset by city
DST Checker
Free online dst checker. when does daylight saving time end, DST dates 2026, clocks change
Unix Timestamp
Free online unix timestamp. unix timestamp converter, epoch time to date, epoch to human
Countdown Timer
Free online countdown timer. countdown timer, days until event, create a countdown online
Days Until Christmas
Free online days until christmas. how many days until Christmas, Christmas countdown 2026
Days Until New Year
Free online days until new year. how many days until New Year, New Year countdown timer
Pregnancy Due Date
Free online pregnancy due date. pregnancy due date calculator, when is my due date, LMP date
Wedding Countdown
Free online wedding countdown. days until my wedding, wedding date countdown timer online
Anniversary Calculator
Free online anniversary calculator. anniversary calculator, days since [date], how long together
Seconds Converter
Free online seconds converter. seconds to minutes, convert seconds to hours minutes seconds
Minutes to Hours
Free online minutes to hours. minutes to hours, convert 90 minutes to hours, min to hr
Hours to Days
Free online hours to days. 48 hours to days, how many days is 72 hours, hours to days
Weeks to Days
Free online weeks to days. weeks to days, how many days in X weeks, 2 weeks in days
Months to Days
Free online months to days. how many days in a month, months to days, 3 months in days
Years to Days
Free online years to days. how many days in a year, years to days, 2 years in days
Calendar Generator
Free online calendar generator. calendar generator, printable calendar 2026, blank calendar template
Leap Year Calculator
Free online leap year calculator. is 2026 a leap year, leap year calculator, next leap year date
Days in Month
Free online days in month. how many days in [month], days in February 2026, days per month
Days in Year
Free online days in year. how many days in 2026, days in a year, total days this year
What Day Is Today
Free online what day is today. what day is today, today date and day of week, current date
Holiday Calendar
Free online holiday calendar. 2026 public holidays US UK India, holiday calendar, bank holidays
Quarter Calculator
Free online quarter calculator. what quarter is [month], Q1 Q2 Q3 Q4 dates 2026, fiscal quarter
Fiscal Year Calculator
Free online fiscal year calculator. fiscal year calculator, FY dates, financial year end date
Week Number Calculator
Free online week number calculator. what week number is it, week number 2026, ISO week number today
Weeks Between Dates
Free online weeks between dates. how many weeks between two dates, weeks calculator
Weeks From Now
Free online weeks from now. 4 weeks from now, 12 weeks from today, date in X weeks
Weeks Ago Calculator
Free online weeks ago calculator. 6 weeks ago, what date was 8 weeks ago from today
Add Weeks to Date
Free online add weeks to date. add weeks to a date, date plus X weeks, future date in weeks
Week Calendar 2026
Free online week calendar 2026. week numbers 2026, ISO week calendar, printable week calendar
Pregnancy Due Date
Free online pregnancy due date. pregnancy due date calculator, when is my due date, LMP
Weeks Pregnant
Free online weeks pregnant. how many weeks pregnant am I, weeks pregnant by date
Baby Age Calculator
Free online baby age calculator. baby age calculator, how old is my baby in weeks months
IVF Due Date
Free online ivf due date. IVF due date calculator, embryo transfer due date, 5dt
Ovulation Calculator
Free online ovulation calculator. ovulation calculator, fertile window, best time to conceive
Gestational Age
Free online gestational age. gestational age calculator, how far along am I
Period Calculator
Free online period calculator. period calculator, next period date, menstrual cycle
Medication Schedule
Free online medication schedule. medication schedule calculator, dose timing, take every X hours
Days Alive Calculator
Free online days alive calculator. how many days have I been alive, days alive calculator
1 Billion Seconds
Free online 1 billion seconds. when will I be 1 billion seconds old, milestone
Life in Weeks
Free online life in weeks. life in weeks visualizer, life expectancy weeks grid
Relationship Duration
Free online relationship duration. how long together, relationship anniversary days
Sober Days Counter
Free online sober days counter. sober days counter, how long have I been sober, sobriety
Sleep Calculator
Free online sleep calculator. sleep cycle calculator, what time should I wake up
Retirement Countdown
Free online retirement countdown. how many days until retirement, countdown timer
Unix Timestamp Converter
Free online unix timestamp converter. unix timestamp converter, epoch to date, timestamp
ISO 8601 Converter
Free online iso 8601 converter. ISO 8601 format, ISO date converter, RFC 3339 date string
Cron Expression Builder
Free online cron expression builder. cron expression builder, cron job scheduler, syntax
Timezone API Reference
Free online timezone api reference. timezone list API, IANA timezone names, timezone offset
Date Format Reference
Free online date format reference. date format codes, MM DD YYYY formats, strftime codes
Milliseconds Converter
Free online milliseconds converter. milliseconds to seconds, convert ms to minutes, epoch ms
Date Diff Code Snippets
Free online date diff code snippets. calculate date difference JavaScript Python snippets
Invoice Due Date
Free online invoice due date. invoice due date calculator, net 30 due date
Loan Maturity Date
Free online loan maturity date. loan maturity date calculator, payoff date
Contract Expiry
Free online contract expiry. contract expiry calculator, lease end date
Statute of Limitations
Free online statute of limitations. statute of limitations calculator
Probation End Date
Free online probation end date. probation period calculator, when ends
Maternity Leave Date
Free online maternity leave date. maternity leave end date, leave dates
Notice Period Calc
Free online notice period calc. notice period calculator, last working day, 2 weeks notice
Sunrise & Sunset
Free online sunrise & sunset. sunrise sunset calculator, what time is sunrise today
Moon Phase Calculator
Free online moon phase calculator. moon phase calculator, what phase is moon tonight
Daylight Hours
Free online daylight hours. hours of daylight today, daylight hours calculator
Solstice & Equinox
Free online solstice & equinox. summer solstice 2026, equinox dates, first day spring
Golden Hour Calculator
Free online golden hour calculator. golden hour calculator, magic hour photography time
Full Moon Calendar
Free online full moon calendar. full moon calendar 2026, next full moon date
Season Calculator
Free online season calculator. what season is it, current season by date, season dates
N Days From Today
Free online n days from today. 30 days from today, 60 days from today, 90 days from today — N=1..365
N Days Ago
Free online n days ago. 30 days ago, 60 days ago, 90 days ago — mirror going backward N=1..365
N Weeks From Today
Free online n weeks from today. 2 weeks from today, 6 weeks from today, 12 weeks — N=1..52
N Months From Today
Free online n months from today. 3 months from today, 6 months from today — N=1..24
Days Until [Holiday]
Free online days until [holiday]. days until Christmas, Diwali, Eid, Halloween — one per holiday × country
What Day Was [Date]
Free online what day was [date]. what day was January 1 2000 — generate for 200+ famous historical dates
How Long Until [Year]
Free online how long until [year]. how long until 2030, 2028 Olympics — flips to 'since' automatically
Why Use DateTimeLab?
🎯 Precision Math
Accounts for leap years, differing month lengths, and daylight saving shifts automatically.
⚡ Zero Latency
Instant calculations run locally inside your browser, ensuring no waiting times or page refreshes.
🆓 100% Free
No subscriptions, no account signup required, and no usage limitations. Completely public utility.
🔒 Privacy-First
Your inputs are calculated in your browser memory and never uploaded or stored on any server.
About the Expert Creator
Vipul Jaganiya is a Computer Science graduate specializing in Calendar Mathematics and Timezone Engineering. DateTimeLab is built to eliminate inconsistencies in standard time mathematics, providing high-fidelity, standards-compliant utilities.