Time & Date Tools
Precision tools for calculating duration, converting time zones, managing dates, and tracking work hours.
Our time and date calculators handle everything from simple age calculations to complex multi-timezone meeting planning. Each tool uses the same reliable time zone database as your operating system, with automatic daylight saving time handling. You might also find our Calculate hourly to annual salary, Project investment growth over time, Calculate loan payoff dates, Plan retirement timeline, Calculate startup runway, Estimate travel times, Plan HSA contributions and Track learning progress over time helpful for related calculations.
Time & Date Tools Guide
Last updated: February 17, 2026
Last updated: February 17, 2026
What you can do in Time & Date Tools
- •Calculate exact age in years, months, days, hours, minutes, and seconds with leap year handling
- •Find the difference between two dates in multiple units (days, weeks, business days, months, years)
- •Count business days excluding weekends and customizable holidays (US federal, bank, custom)
- •Convert times across time zones with automatic daylight saving time adjustments
- •Plan meetings across multiple time zones with overlapping availability visualization
- •Calculate work hours, overtime, and pay from time card entries with break handling
Accuracy, assumptions, and sources
- •All calculations use the Gregorian calendar and IANA Time Zone Database (same as operating systems and browsers).
- •Daylight saving time transitions are handled automatically based on location-specific rules, updated as governments change DST.
- •Business day calculations assume Monday-Friday work weeks. Holidays default to US federal holidays unless customized.
- •Date arithmetic follows ISO 8601 conventions. Month calculations account for varying month lengths.
- •Leap year rules: divisible by 4, except century years unless also divisible by 400 (1900 wasn't, 2000 was).
- •Time zone conversions use current rules. Historical dates may use rules that were different at that time.
Pick the right calculator fast
- If you want to know someone's exact age→Age Calculator
- If you need days or weeks between two dates→Date Difference Calculator
- If you're counting working days for project deadlines→Business Days Calculator
- If you want a countdown to an event→Countdown to Date / Event Builder
- If you need to calculate hours worked and overtime pay→Work Hours & Overtime Calculator
- If you're scheduling across time zones→Time Zone Meeting Planner
- If you want to know if a year is a leap year→Leap Year & Calendar Helper
- If you need time elapsed since or until a date→How Long Since / Until
Common mistakes to avoid
- •Confusing calendar days with business days for project deadlines—business days exclude weekends and holidays.
- •Forgetting that 'months' vary in length (28-31 days), making month-based calculations approximate.
- •Ignoring daylight saving time when scheduling across time zones—times shift by an hour twice yearly.
- •Using local time without specifying time zone. Always clarify whether times are local, UTC, or a specific zone.
- •Assuming all countries observe the same holidays. Business day calculations need region-specific holiday lists.
- •Not accounting for the International Date Line when crossing Pacific time zones.
- •Calculating age without considering whether the birthday has occurred yet this year.
- •Forgetting that some time zones have 30 or 45-minute offsets (India: UTC+5:30, Nepal: UTC+5:45).
Editorial policy
- ✓All calculators provide accurate results based on standard calendar rules and official time zone databases.
- ✓Time zone data follows IANA standards, updated when governments announce DST or time zone changes.
- ✓We don't store your dates or personal information. All calculations run client-side in your browser.
- ✓Date formats follow ISO 8601 (YYYY-MM-DD) internally, with localized display options.
- ✓Found an error? Email us at hello@everydaybudd.com and we'll fix it promptly.
- ✓Tools are updated when time zone rules change or calendar calculation standards are refined.
Top Picks
All Time & Date Tools Tools
Frequently Asked Questions
How accurate are the time zone conversions?
Our calculators use the IANA Time Zone Database, the same source used by operating systems and programming languages worldwide. We automatically handle daylight saving time transitions for all supported regions, updated as governments change DST rules.
Does the Age Calculator account for leap years?
Yes, our Age Calculator properly handles leap years, including the century rules (1900 wasn't a leap year, 2000 was). It calculates exact age in years, months, and days, accounting for varying month lengths and February 29th birthdays.
How does the Date Difference Calculator handle business days?
Our Business Days Calculator excludes weekends (Saturday/Sunday) by default. You can also exclude common US federal holidays or add custom holidays. For international use, verify holiday lists match your country's calendar.
What date formats are supported?
Our tools accept ISO 8601 (YYYY-MM-DD), US format (MM/DD/YYYY), European format (DD/MM/YYYY), and natural language ('next Tuesday', 'in 3 weeks'). Results display in your preferred format. ISO 8601 is recommended to avoid ambiguity.
Can I calculate dates across different calendar systems?
Our tools primarily use the Gregorian calendar. For historical dates before October 15, 1582 (when Gregorian was adopted), results assume proleptic Gregorian extension. We don't currently convert to/from lunar, Hebrew, or Islamic calendars.
How do I schedule meetings across multiple time zones?
Use our World Clock / Time Zone Converter. Add all participants' cities to see overlapping business hours highlighted. The tool shows 'golden hours' where all zones have reasonable working times (typically 8am-6pm local).