Date, Time & Scheduling Tools

Live POSIX telemetry countdown, two's complement binary register visualizer, and 32-bit time_t integer overflow simulator for the Unix Year 2038 Epochalypse.

Model biological circadian desynchronization, recovery day timelines, sleep phase schedules, and phototherapy windows for DST shifts and international jetlag.

Enterprise browser-based Critical Path Method (CPM) scheduler. Computes Early Start, Early Finish, Late Start, Late Finish, Total Float, and exact calendar finish dates for complex task networks.

Audit mid-cycle hires, employee departures, and unpaid leaves with precise working business days, hourly shift rates, and statutory salary proration formulas.

Parse, build, combine, and calculate arithmetic intervals for ISO-8601 duration strings (PnYnMnDTnHnMnS) with calendar-aware date anchoring.

Enterprise bidirectional Gregorian to Hebrew lunar-solar calendar date conversion engine featuring 19-year Metonic cycle calculations, Molad conjunctions, Dechiyot postponement rules, Shmita tracking, and Jewish holiday detection.

Bi-directional conversion between the Islamic Hijri lunar calendar and Gregorian solar calendar with Umm al-Qura algorithms, moon-sighting adjustment, and Arabic script rendering.

Calculate the exact Equation of Time (EoT) disparity between solar sundial time and civil clock time. Features an interactive figure-8 analemma curve visualizer with Keplerian orbital eccentricity and ecliptic obliquity decomposition.

Enterprise BigInt timestamp parser and RFC 3339 / ISO 8601 normalizer with sub-millisecond nanosecond precision for distributed tracing and Kafka streams.

Calculate Greenwich Mean Sidereal Time (GMST), Greenwich Apparent Sidereal Time (GAST), Local Sidereal Time (LAST), and Local Hour Angle (LHA) with IAU nutation algorithms.

Audit quarterly working days, federal bank holidays, corporate shut-downs, billable hours capacity, and revenue forecasts across Q1, Q2, Q3, and Q4.

Calculate bi-weekly, semi-monthly, weekly, and monthly paydays, identify 3-paycheck magic months, adjust for weekends, and export payroll schedules to CSV.

Convert decimal hours to standard hours, minutes, and seconds (HH:MM:SS) for payroll, timesheets, legal 6-minute billing, and invoicing.

Convert 24-hour military time to standard 12-hour AM/PM format with verbal speech audio pronunciation, NATO radio phonetics, batch manifests, and conversion tables.

Calculate exact target dates by adding or subtracting business days. Accounts for weekends, custom workweeks, and statutory federal holidays.

Interactive astronomical trajectory explorer for upcoming solar and lunar eclipses, totality paths, and visibility zones.

Estimate degree completion dates, credit roadmaps, and semester pacing for college and school.

Forecast future bill due dates, weekend business-day shifts, and annualized cash flow for subscriptions and recurring payments.

Forecast habit streak durability, calculate target milestone probabilities, and track 66-day automaticity metrics using UCL behavioral modeling.

Convert between calendar dates, Julian Day (JD), Modified Julian Date (MJD), Reduced Julian Date (RJD), and Sidereal Time (GMST) with precision astronomical epoch calculations.

Calculate exact solar noon culmination time, solar zenith, altitude, azimuth angles, and daylight hours with NOAA precision.

Convert part-time hours, shifts, and team rosters into standardized Full-Time Equivalents (FTE), ACA employer mandates, and payroll metrics.

Calculate daily and weekly work hours, lunch break deductions, overtime (1.5x), California daily double time (2.0x), and export payroll CSVs.

Find perfect cross-timezone meeting overlaps, schedule remote team calls across international working hours, and export ICS calendar invites.

Circadian focus sprint intervals, task batching, and flow state ergonomics.

Calculate accurate lunar phases, illumination percentages, moon age, distance, and monthly lunar calendar views.

Calculate accurate sunrise, sunset, twilight phases, golden hour, and daylight duration for any coordinates.

Create customizable, embeddable countdown timers for launches, sales, and events.

Calculate ISO-8601 week numbers, week date ranges, and annual week metrics.

Determine the exact day of the week for any past, present, or future calendar date instantly.

Instantly check leap years, century leap rules, and date range schedules.

Convert live and scheduled time across multiple international time zones simultaneously.

Calculate exact days between dates, net business working days, and perform date addition or subtraction in real-time.

Calculate exact days between dates, working business days, total weeks, and perform date addition or subtraction.