Ultimate Date & Time Tools

From counting business days to calculating your exact age, we handle every calendar and clock calculation with professional precision.

Date Tools Business Days Tools Age & Birthday Tools Time Calculators Time Converters

Specialized Date Calculator Tools

Need something more focused than a generic date calculator? These tools cover common long-tail queries like “days between two dates”, “days between dates excluding weekends”, “add days/months safely”, or “countdown to a date”. All calculations run locally in your browser.

Date Calculator

Calculate date differences and offsets quickly. Clean inputs, instant results, copy-ready output.

Days Between Dates

Simple day difference between two dates. Useful for planning, reporting, and quick checks.

Days Between Dates (with Time)

Include time-of-day for precise durations. Outputs days, hours, minutes, and total seconds.

Days Between Dates (Excluding Weekends)

Exclude Saturdays and Sundays automatically. Great for scheduling and work timelines.

Days Between Dates (Inclusive)

Count both start and end date. Handy for leave periods, bookings, and “how many days total?”

Add Months to Date

Month-end safe (31st → 30th/28th/29th). Presets (+1/+3/+6/+12) and adjustment indicator.

Add Days to Date

Pick a start date and add N days. Quick presets (+7/+14/+30/+90) and copy-ready output.

Future Date Calculator

No date picker: calculate N days from today fast. Presets (30/60/90/180/365) + big output.

Subtract Days from Date

Go back N days for history/reporting. Presets (-7/-30/-90/-365) plus weeks difference + ISO.

Countdown to Date

Live ticking countdown to any date/time. Shows days left, HH:MM:SS, totals, and embed code.

Start here if you want the all-in-one tool: Date Calculator.

Business Days & Workday Calculators

Calculating timelines for work and delivery often means ignoring weekends and counting only weekdays. These tools help with queries like “business days between two dates”, “add business days to a date”, or “deadline in N business days”. Everything runs locally in your browser.

Business Days Calculator

General-purpose workday tool for common “weekday-only” calculations, with clear outputs and totals.

Business Days Between Dates

Count weekdays between two dates (Mon–Fri). Great for project planning, SLAs, and reporting.

Deadline Calculator (Business Days)

Find the deadline date after N business days. Perfect for “due in 10 workdays” scenarios.

Add Business Days to Date

Add weekdays only (skips weekends). Ideal for shipment estimates, approvals, and turnaround times.

For calendar-day differences, see the Days Between Dates tools.

Age, Birthday & Birth Date Calculators

From simple age checks to niche cases like leap-year birthdays, these tools cover queries like “how old am I”, “when is my next birthday”, “age in days”, or “calculate birth date from age”. All calculations run locally in your browser.

Age Calculator

Calculate exact age from a birth date. Shows years/months/days and useful totals.

Birthday Calculator

See birthday details like day of week, how many days since birth, and quick shareable results.

Next Birthday Calculator

Find the date of your next birthday plus how many days remain. Great for planning ahead.

Leap Year Birthday Calculator

Born on Feb 29? See celebration options and next matching leap-year date.

Birthday Countdown

Live countdown to your next birthday. Shows days/hours/minutes and totals.

Age in Days

Convert your age to total days lived (and often hours/minutes). Fun + useful for milestones.

Birth Year Calculator

Estimate birth year from age (and optionally reference date). Great for quick checks and forms.

Calculate Birth Date from Age

Reverse-calculate the birth date given an age and reference date. Helpful for validation and records.

Chronological Age Calculator

More detailed age breakdown for official contexts. Clear units and multiple formats.

How Old Will I Be in 2035

Future-age calculator for a fixed year. Great for retirement planning and long-term milestones.

Want a general date tool instead? Try Date Calculator.

Time Calculators & Scheduling Helpers

For planning work, tracking durations, or converting time blocks, these tools handle queries like “time duration calculator”, “add/subtract hours”, “week number”, or “what day of the week is this date?”. Everything runs locally in your browser.

Time Calculator

Add/subtract time values (hours/minutes/seconds) with clean inputs and instant results.

Time Duration Calculator

Compute duration between two times or timestamps. Great for shifts, logs, and time tracking.

Hours Calculator

Sum hours across multiple entries (work logs, timesheets). Quick totals and easy copy.

Week Number Calculator

Find the ISO week number for a date. Useful for business planning and reporting cycles.

Day of Week Calculator

Instantly see what day of the week a date falls on. Handy for events and scheduling.

Need unit conversions (seconds ↔ minutes ↔ hours)? See the Time Converters section below.

Time & Unit Converters (Seconds, Minutes, Hours, Days)

Convert time units fast for reporting, engineering, and everyday use. These tools cover queries like “seconds to HH:MM:SS”, “minutes to hours”, “hours to days”, “days to weeks”, and “Unix timestamp converter”. All conversions run locally in your browser.

Time Converter

General converter for common time units. Quick input, instant output, easy copy.

Time Zone Converter

Convert times across time zones for meetings and remote teams. Clear offsets and results.

Unix Timestamp Converter

Convert Unix timestamps ↔ human-readable dates. Great for logs, APIs, and debugging.

Duration to Seconds

Convert a duration to total seconds for tech use cases (rate limits, timers, analytics).

Days to Weeks

Quickly convert days to weeks (including decimals). Helpful for planning and estimates.

Weeks to Days

Convert weeks to days instantly. Great for schedules and contracts.

Hours to Days

Convert hours into days (and fractions). Useful for task estimates and reporting.

Minutes to Hours

Convert minutes to hours for timesheets and analytics. Fast, clean, and copyable.

Seconds to HH:MM:SS

Turn seconds into an HH:MM:SS clock format. Perfect for video, audio, and timers.

Seconds to Minutes

Convert seconds into minutes (with decimals). Great for quick calculations and KPIs.

Milliseconds to Seconds

Convert ms ↔ seconds for performance metrics and debugging (TTFB, latency, timers).

Need to calculate durations (not just convert)? Use Time Duration Calculator.

Professional Tools for Time Management

In our modern, interconnected world, managing time isn't just about glancing at a watch—it's about planning fiscal years, monitoring project milestones, and celebrating milestones. DateTools.live was built to provide the most accurate, secure, and user-friendly experience for these calculations.

Secure & Private Calculations

Unlike other online tools, we value your privacy. All calculations happen locally in your browser. Your dates of birth, working hours, and personal timelines are never sent to a server, ensuring your data remains yours.

Optimized for Speed

Every calculator on this site is built with vanilla JavaScript. This means no heavy libraries to download, resulting in near-instant load times even on slow mobile connections. Whether you're in the office or on the move, DateTools.live is ready when you are.