๐ Date & Time Calculators
Age, D-Day countdowns, days between dates, adding days and weekly work hours โ counting days and hours, done right.
018 tools
Age Calculator
Exact age in years, months and days, days until your next birthday, plus Korean age explained.
โDays Until Calculator (D-Day)
Countdown to any date or days since a past date, with 100-day, 1,000-day and yearly milestones.
โDays Between Dates Calculator
Days between two dates in days, weeks, months and years, plus weekdays (MonโFri) and weekend days.
โDate Calculator (Add/Subtract)
Add or subtract days, weeks, months, years or business days from a date and get the weekday.
โWork Hours Calculator (Korea)
Weekly hours, overtime and 10 PMโ6 AM night work from shift times, with pay under Korean labor law.
โKorean Military Discharge Date Calculator
Discharge date, days left and percent served for South Korean Army, Navy, Air Force and Marines.
โSleep Calculator
Best bedtime or wake-up time based on 90-minute sleep cycles, plus power nap alarm times.
โAnniversary Calculator
Day count since you got together and your 100-day, 1,000-day and yearly anniversaries, Korean style.
โWhen to use what
Use the age calculator for forms, insurance and contracts, the D-Day calculator for exams, trips and anniversaries, the date difference calculator for contract periods or days of service, and the work hours calculator to total a week of shifts and overtime.
How days are counted
A date difference can be off by one depending on whether the start day is included, so the result shows both. International age (years completed since birth) is used throughout.