Date & Time

Free Birthday Calculator — find your exact age in years, months and days, days until your next birthday, zodiac sign, Chinese zodiac, birthstone, birth flower, generation, planet ages, and more.

Free Blue Moon Calculator — find the next monthly and seasonal blue moon dates, countdowns, named full moon lists, supermoon tags, and iCal export for any year range.

Free Data Storage Conversion Calculator — instantly convert between bits, bytes, kilobytes, megabytes, gigabytes, terabytes, and IEC binary units (KiB, MiB, GiB) with a real-time all-units table, transfer time estimator, and binary vs decimal comparison.

Free Date Difference Calculator — instantly find the exact number of days, weeks, months, and years between any two dates. Includes business days mode, time breakdown, and milestone detection.

Free Date Duration Calculator — instantly find the number of days, weeks, months, and years between any two dates. Includes business days, hours, minutes, seconds, calendar-accurate breakdown, and batch mode.

Free Leap Year Calculator — check if any year is a leap year, find all leap years in a range, view step-by-step divisibility checks, February mini-calendar, countdown to the next Feb 29, and century analysis.

Free Time Duration Calculator — calculate the duration between two dates/times, add or subtract time from a date, and convert between time units like seconds, minutes, hours, days, weeks, months, and years.

Free Business Days Calculator — count working days between two dates or add/subtract business days from a start date. Excludes weekends, US federal holidays, and custom dates.