Date Difference
Days Between Dates Calculator: US Business Days
start date ↔ end dateCalculate days between two dates: total days, business days, weeks between dates, and weekend days. Exclude weekends and US federal holidays for accurate HR payroll and project tracking.
Business Days Calculator: US Workdays Minus Holidays
dates ↔ workdaysCount working business days between two US dates: add days to date exclude weekends, subtract days from date, and calculate deadline dates. Automatically excludes weekends and all 11 US federal holidays.
US School Days Calculator: Excluding Breaks & Holidays
start date → end dateEstimate US school days between two dates, excluding weekends, federal holidays, and typical summer/winter/spring breaks. Approximate national-average estimate — always verify against your local district calendar.
Custom Holiday Calculator: Business Days Excluded
dates + custom exclusionsCalculate working days between two US dates while excluding your own custom list of holidays, closures, or non-working days.
Date Duration Calculator: Years to Seconds Between Dates
start date ↔ end dateCalculate the full duration between two dates broken down into years, months, weeks, days, hours, minutes, and seconds. Perfect for US anniversaries, contract terms, and elapsed-time tracking.
Date Arithmetic
Date Calculator: Add/Subtract Days, Weeks & Months
date ± unitsAdd days to date exclude weekends, subtract days from date calculator, calculate deadline date work days. Perfect for US tax deadlines, contract periods, and project scheduling.
Days Until Calculator: Holidays, Tax & Project Countdown
today ↔ targetCountdown to any future US date: days until deadline, days until holiday, project timeline countdown. Shows days, weeks, months, and years remaining with business day option.
US Holiday Countdown: Thanksgiving, Christmas & Tax Day
today → holidayCountdown to major US holidays and events like Thanksgiving, Christmas, Tax Day, Fourth of July, and more. Always up-to-date for the next occurrence.
Working Days Left in 2026: US Business Days Remaining
today → year-end workdaysCount how many working days are left in 2026 from any date, automatically excluding weekends and all 11 US federal holidays. Perfect for US payroll planning, project deadlines, and revenue forecasting.
Calendar Reference
Week Number Calculator - US vs ISO Work Week Standard
date ↔ week #Find the US and ISO week number for any date. Understand how American business weeks differ from the international ISO standard.
Leap Year Checker - US Calendar & Legal Date Compliance
year ↔ leap statusCheck whether any year is a leap year under US Gregorian calendar rules. See February day count and total year days for compliance.
What Day Is This Date? Weekday Finder - US Date Day of Week
date → weekdayFind what day of the week any date falls on. Perfect for US tax deadlines, contract dates, appointments, and planning around the American workweek.
Unix Timestamp Converter: Epoch to Date & Back (UTC)
timestamp ↔ dateConvert Unix timestamps (epoch seconds) to human-readable dates and back. Shows ISO 8601, relative time, and millisecond precision for US developers and log analysis.
Quarter Calculator - Find the US Fiscal Quarter for Any Date
date → quarterFind which US fiscal quarter (Q1-Q4) any date falls in, with quarter start and end dates, total days, and current-quarter status. Perfect for US business reporting and tax planning.
Day of Year Calculator - Find Day Number 1-366 for Any Date
date → day #Find the day of the year (1-366) for any date, plus days remaining, US week number, and year-progress percentage. Perfect for US annual planning and ordinal date tracking.
Personal & Time
Age Calculator - Exact US Age in Years, Months & Days
birth ↔ ageCalculate exact age in years, months, and days following US standards. Includes total days lived and next-birthday countdown.
US Time Zone Converter: PST/EST/UTC with DST
zone ↔ zoneConvert times between US time zones: PST to EST, PDT to EDT, CST to EST, MST to EST, UTC to PST, UTC to EST. Automatic daylight saving time (DST) handling for all American time zones.
Countdown Timer - Set Time, Seconds, Minutes, Hours & Days
target → countdownFree online countdown timer. Set a target date and time, or enter seconds, minutes, hours, or days. Watch it count down with days, hours, minutes, and seconds.
Full Retirement Age Calculator by Birth Year (SSA)
birth date → SSA FRAFind your Social Security full retirement age (FRA) by birth year — 66 to 67, counted month by month per SSA rules — and the exact date you reach it. Includes early (62) and delayed-credit (to 70) reference points.
Payroll & Work
US Payroll Hours Calculator - Overtime, Weekly Hours & Pay
hours × rate = payCalculate US payroll hours and pay with overtime (1.5x), double time, and weekly hour caps. Perfect for hourly workers, part-time staff, and small business HR.
Time Card Calculator: Weekly Timesheet & Overtime (US)
clock in/out → hours & payCalculate weekly time card hours from clock-in and clock-out times, with break deductions and FLSA overtime pay. Perfect for US hourly workers, timesheets, and small business payroll.
Years of Service Calculator: Employment Tenure
hire date → tenureCalculate years of service and employment tenure from your hire date — exact years, months, and days worked, plus your next anniversary. For HR, seniority, vesting, FMLA.
Data sources & methodology
- State labor departmentsPaid sick leave statutes and agency guidance for all 50 states + DC.
- Public aggregatessmallbizhandbook / postercompliance / inovapayroll 2026 state tables (retrieved 2026-08-23).
- Local ordinancesCity and county codes stricter than state law (e.g. SF, Chicago, Seattle, NYC).
Methodology and citations are maintained by the DayFig editorial team. Where an official schedule is not yet loaded, results are shown as model estimates and the source is stated as a reference.