Time & Date Tools
Create clocks and calendars, convert and compare times, perform accurate calendar arithmetic, format values and sort temporal data.
Popular tools
Draw a Memento Mori Calendar
Visualize elapsed and remaining weeks across a selected illustrative lifespan.
Draw an Analog Clock
Generate an accurate analog clock face as a downloadable SVG image.
Draw a Digital Clock
Create a styled digital clock graphic with optional seconds.
Draw a Monthly Calendar
Generate a validated Sunday-first calendar for any Gregorian month.
Generate Palindromic Clock Times
Find clock times that read identically forward and backward without the colon.
Generate Palindromic Calendar Dates
Find valid YYYYMMDD dates that read identically in both directions.
Convert Time to Seconds
Convert a clock-style duration into exact total seconds and milliseconds.
Convert Seconds to Time
Convert positive or negative seconds into a day and HH:MM:SS duration.
Universal 12/24-Hour Clock Converter
Convert 12-hour, 24-hour and military clock times with synchronized analog and digital visualization, batch conversion and clear explanations.
Convert 24 Hour Clock Time to 12 Hour Clock Time
Convert a validated 24-hour time to AM/PM notation.
Convert 12 Hour Clock Time to 24 Hour Clock Time
Convert a validated AM/PM time to 24-hour notation.
Find Time Difference
Calculate an elapsed clock-time duration with optional overnight handling.
Clocks & Calendars
Find Date Difference
Calculate calendar years, months, days, total days and direction between dates.
Find Age Difference
Calculate the exact calendar and total-day gap between two birth dates.
Increment a Calendar Date
Add days, weeks, months or years using accurate Gregorian calendar arithmetic.
Decrement a Calendar Date
Subtract days, weeks, months or years with safe end-of-month behavior.
Sort Calendar Dates
Validate and sort ISO calendar dates in ascending or descending order.
Generate Magic Calendar Dates
Find valid dates with repeated or sequential month-and-day digit patterns.
Format a Calendar Date
Format a Gregorian date with numeric, month-name and weekday tokens.
Round a Calendar Date
Round a date to the nearest week, month or year boundary.
Validate a Calendar Date
Validate Gregorian dates and reject impossible values.
Truncate a Calendar Date
Move a date to the first day of its current week, month or year.
Generate Random Calendar Dates
Generate seeded random dates inside a selected range.
Generate Custom Calendar Dates
Generate dates between boundaries at a custom day step.
Split Date into Intervals
Split a calendar date range into equal intervals.
Convert Gregorian Calendar to Julian Calendar
Convert a Gregorian date into its Julian calendar date.
Convert Julian Calendar to Gregorian Calendar
Convert a Julian calendar date into Gregorian form.
Convert a Julian Day to a Date
Convert an astronomical Julian day into a calendar date.
Spell a Calendar Date
Write a calendar date in readable long form.
Add Fuzziness to Calendar Dates
Add reproducible bounded day variation to dates.
Analyze a Calendar Date
Inspect weekday, ordinal, leap, zodiac and Julian details.
Visualize Time Intervals
Draw proportional clock intervals on a text timeline.
Visualize Date Intervals
Draw proportional date ranges on a text timeline.
Sorting & Intervals
ISO, Timestamps & Durations
Sort Time Intervals
Sort durations and clock ranges by calculated length rather than displayed text.
Shift Duration Calculator
Calculate gross and paid shift duration after unpaid breaks.
Overnight Shift Calculator
Calculate work duration for shifts crossing midnight.
ISO 8601 DateTime Parser
Parse strict ISO date-times and inspect every timestamp representation.
ISO 8601 Validator
Validate complete ISO date-times and reject impossible values.
Find ISO Week Number
Find the ISO week-year, week number and weekday for a date.
RFC 3339 Parser
Parse RFC 3339 timestamps through the shared Timestamp Lab.
UNIX Milliseconds Converter
Convert Unix milliseconds through the shared Timestamp Lab.
Excel Serial Date Converter
Convert Excel serial dates into timestamps and calendar dates.
Parse Human Duration
Parse readable durations such as days, hours and minutes.
Parse ISO 8601 Duration
Parse ISO durations and explain calendar-unit approximations.
Duration Calculator
Add, subtract, multiply or divide durations.
Calculate Seconds Till Midnight
Calculate the forward duration from a clock time to the next midnight.
Sort Date Intervals
Sort validated date ranges by their calculated duration.
ISO 8601 DateTime Formatter
Format date-times as normalized ISO 8601 values.
Date to ISO Week Date
Convert a calendar date into ISO week-year, week and weekday.
ISO Week Date to Calendar Date
Convert an ISO week date into a calendar date.
Generate ISO Week Calendar
Generate every ISO week with Monday and Sunday dates.
RFC 3339 Formatter
Format date-times as normalized RFC 3339 timestamps.
UNIX Microseconds Converter
Convert Unix microseconds without losing integer input precision.
UNIX Nanoseconds Converter
Convert Unix nanoseconds through a BigInt timestamp engine.
Windows FILETIME Converter
Convert Windows FILETIME values with exact integer arithmetic.
.NET Ticks Converter
Convert .NET tick counts through the shared Timestamp Lab.
Format Human Duration
Format milliseconds as a readable duration.
Normalize Duration
Normalize human or ISO durations into stable representations.
Scheduling & Recurrence
Business Days Between Dates
Count inclusive workdays using a custom workweek and holiday calendar.
SLA Deadline Calculator
Calculate an SLA deadline within business hours and holidays.
Business Calendar Calculator
Apply one reusable custom workweek, hours, break, timezone and holidays.
Convert Recurring Meetings Across Timezones
Convert recurring wall-time meetings while DST offsets evolve.
Cron Expression Parser
Parse five-field cron expressions into structured fields.
Cron Expression Generator
Build and validate a five-field cron schedule.
Cron Expression Validator
Validate ranges, lists, steps and named cron values.
Explain Cron Expression
Explain a five-field cron expression in plain language.
Find Next Cron Run Times
Calculate upcoming UTC cron run times.
Cron Schedule Visualizer
Display upcoming cron executions as a numbered timeline.
RRULE Generator
Generate supported RFC-style recurrence rules.
RRULE Parser
Parse recurrence rules into structured JSON properties.
RRULE Validator
Validate supported daily, weekly, monthly and yearly rules.
Find Next Recurring Dates
Generate future dates from a recurrence rule.
Recurring Date Calculator
Build a recurrence and calculate all resulting dates.
Monthly Recurrence Calculator
Generate nth-weekday monthly schedules.
Holiday Calendar Generator
Generate a deterministic holiday calendar preset.
Adjust Deadline for Holidays
Move a deadline away from weekends and custom holidays.
Subtract Business Days
Move backward through custom working days and holidays.
Count Weekdays Between Dates
Count inclusive Monday-to-Friday dates without holidays.
Find a Specific Day
Find an nth weekday within a selected month.
Find Cron Runs Between Dates
List cron runs inside an exact date-time range.
Find Nth Weekday of Month
Find the first through fifth selected weekday in a month.
Find Last Weekday of Month
Find the final selected weekday in a month.
Holiday Date Finder
Search deterministic GH, US or GB holiday presets.
Observed Holiday Calculator
Move weekend holidays using a selected observation rule.
Business Time & Working Hours
Add Business Days
Calculate a deadline after a selected number of working days.
Find Next Business Day
Find the next valid workday after a selected date.
Working Hours Between DateTimes
Measure actual scheduled working time between two date-times.
Add Working Hours
Calculate a completion date-time after scheduled work hours.
Workday End Time Calculator
Determine when a task finishes under a custom business schedule.
Overtime Hours Calculator
Separate standard and overtime hours and apply a multiplier.
SLA Elapsed Time Calculator
Measure SLA time consumed inside scheduled business hours.
Overlapping Working Hours Finder
Find UTC hours inside every participant’s working window.
Find Previous Business Day
Find the previous valid workday before a selected date.
Subtract Working Hours
Move backward by scheduled work hours through a business calendar.
Break Time Calculator
Separate paid time, paid breaks and unpaid breaks.
Timezone & DST Intelligence
World Time Converter
Convert local wall time between IANA timezones with DST rules.
Multi-City Timezone Converter
Display one instant across multiple cities and IANA zones.
Timezone Meeting Planner
Display a DST-aware 24-hour overlap grid for participants.
Best Meeting Time Finder
Find complete working-hour overlaps across participant timezones.
Timezone Offset Lookup
Find an IANA zone’s UTC offset at an exact instant.
DST Status Checker
Check whether daylight saving time is active at an instant.
DST Transition Finder
List all UTC offset transitions for a zone and year.
DST Gap and Fold Analyzer
Classify a local wall time as nonexistent, unique or ambiguous.
Ambiguous Local Time Checker
Find whether a local wall time maps to two UTC instants.
Invalid Local Time Checker
Detect local wall times that do not exist during DST gaps.
Timezone Schedule Table Generator
Create a downloadable 24-hour table across multiple IANA zones.
Timezone Difference Calculator
Calculate date-specific offset differences between IANA zones.
UTC Offset Converter
Convert date-time values between explicit numeric UTC offsets.
IANA Timezone Lookup
Search the browser’s supported IANA timezone identifiers.
Find Next DST Change
Find the next timezone offset transition within 550 days.
Find Previous DST Change
Find the previous timezone offset transition within 550 days.
Convert Time Between Timezones
Convert local time between IANA zones with DST handling.
Batch & Dataset Intelligence
Batch Date Converter
Convert many calendar dates with explicit slash-date interpretation.
Batch Timezone Converter
Convert local date-time lists between IANA timezones.
Batch Timestamp Converter
Convert lists of Unix timestamps with automatic unit detection.
Batch Date Normalizer
Normalize many dates into ISO format with row-level status.
Detect Date Format
Identify supported date formats and ambiguous slash dates.
Normalize Mixed Date Formats
Normalize mixed date styles without silently guessing ambiguity.
Validate Date Column
Validate a named CSV date column with row-level diagnostics.
Compare Date Columns
Compare two CSV date columns and calculate day differences.
Date & Time Dataset Profiler
Profile validity, formats, range, duplicates and cadence.
Batch Time Converter
Convert many clock times between 12-hour and 24-hour forms.
Extract Dates from Text
Find calendar dates and source positions inside text.
Extract Times from Text
Find 12-hour and 24-hour clock times inside text.
Extract DateTimes from Text
Find combined date-time values inside text.
Find Date Outliers
Find dates unusually far from the dataset median.
Find Missing Dates
Find absent calendar dates inside a sequence range.
Find Duplicate DateTimes
Find date-times that normalize to the same instant.
Conversion & Formatting
Time & Date Studio
Calculate, schedule, convert, compare and process time datasets in one workspace.
Format a Clock Time
Format a validated clock time with documented 12-hour and 24-hour tokens.
Validate a Clock Time
Validate clock times with clear line-level errors.
Convert Days to Hours
Convert fractional days into exact hours.
Convert Hours to Days
Convert fractional hours into exact days.
Find a Zodiac Sign by Date
Find the Western tropical zodiac sign for a date.
Print Dates of All Zodiac Signs
Display the standard date ranges for all zodiac signs.
Generate Random Clock Times
Generate reproducible random clock times from a seed.
Generate Custom Clock Times
Generate clock times between boundaries at a custom step.
Count Weekend Days
Count inclusive Saturday and Sunday dates in a range.
Split Time into Intervals
Split a clock range into equal intervals.
Generate a Time Sequence
Generate a fixed-count clock sequence with a minute step.
Generate a Date Sequence
Generate a fixed-count date sequence with a day step.
Find Leap Years
Find every Gregorian leap year in a selected range.
Find Common Years
Find every non-leap Gregorian year in a range.
Check If a Year Is a Leap Year
Test a year using complete Gregorian leap-year rules.
Check If a Year Is a Common Year
Test whether a year contains exactly 365 days.
Convert a Date to a Julian Day
Convert a Gregorian date into an astronomical Julian day.
Find Easter Dates
Calculate Western Easter Sunday dates across years.
Convert UNIX Time to Human Time
Convert Unix epoch seconds into ISO human-readable time.
Convert Human Time to UNIX Time
Convert an ISO instant into Unix epoch seconds.
Generate a UNIX Time Sequence
Generate an arithmetic sequence of Unix timestamps.
Generate Random UNIX Time
Generate seeded Unix timestamps inside a selected range.
Convert Regular Time to Military Time
Convert AM or PM clock time into four-digit military time.
Convert Military Time to Regular Time
Convert four-digit military time into AM or PM form.
Spell a Clock Time
Write a validated clock time using English words.
Add Fuzziness to Clock Times
Add reproducible bounded minute variation to clock times.
Find Day of the Week
Find the weekday name for a Gregorian date.
Find Day of the Year
Find a date’s ordinal position within its year.
Find Week of the Year
Find the ISO-style week number for a date.
Find Date by Day of the Year
Convert a year and ordinal day into a date.
Calculate Clock Hand Angle
Calculate precise hour and minute hand angles.
Set Clock Hand Angle
Find whole-minute clock times matching a hand angle.
Find Friday the 13th
Find every Friday the thirteenth across a year range.
Find July the 4th
Generate July fourth dates across a year range.
Find the Christmas Day
Generate Christmas Day dates across a year range.
Find the New Year's Day
Generate New Year’s Day dates across a year range.
Find the Thanksgiving Day
Calculate US Thanksgiving dates across a year range.
Analyze a Clock Time
Inspect clock components, seconds and 12-hour form.
Mirror a Clock Time
Calculate the reflected position on a 12-hour clock.
Convert Time Between Countries
Convert time using documented representative country zones.
Find Season by Date
Find the astronomical season for either hemisphere.
Generate Every N Weekdays
Generate a sequence counting Monday through Friday only.
Pattern Generators
Differences & Elapsed Time
Calculate Seconds Since Midnight
Calculate elapsed seconds and percentage of day from midnight to a clock time.
Calculate Average Time
Calculate the arithmetic mean of validated clock times.
Calculate Average Date
Calculate the midpoint average of multiple dates.
Convert Cat's Age to Human Years
Estimate cat age using a documented staged model.
Convert Human's Age to Cat Years
Invert the documented staged cat-age model.
Convert Dog's Age to Human Years
Estimate dog age using a documented logarithmic model.
Convert Human's Age to Dog Years
Invert the documented logarithmic dog-age model.
Date & Time Arithmetic
Increment a Clock Time
Add seconds, minutes or hours to a clock time and report midnight crossings.
Decrement a Clock Time
Subtract seconds, minutes or hours from a clock time and report day offsets.
Round a Clock Time
Round a clock value to the nearest minute, interval or hour.
Truncate a Clock Time
Move a clock time to the beginning of its current minute interval or hour.