All Tools

Find the week number for any date, or look up the date range for a week. Supports ISO 8601 and US week numbering standards.

Find which day of the week any date falls on. Instantly see the weekday name, ISO day number, week number, and a visual month calendar.

Count business days between two dates or find a date after adding workdays. Excludes weekends and public holidays, with a visual calendar and salary estimate.

Create printable monthly and yearly calendars with custom themes, holidays, events, background images, and PDF export.

Calculate the exact number of days, weeks, and months between any two dates with business day counting and calendar visualization.

Run multiple stopwatches at once in your browser. Name and color-code each one, record laps, and time several people, workouts, or tasks in parallel.

Set multiple alarms in your browser with custom sounds, repeat schedules, snooze, and a live countdown. No install, no account, everything stays on your device.

Convert Unix timestamps to human-readable dates and back. Auto-detects seconds or milliseconds, shows Local, UTC, and ISO 8601 formats, and batch converts.

Find the best meeting time across time zones. Add participants, compare their working hours on a shared timeline, and see overlapping slots that work for everyone.

Convert between kg/m³, g/cm³, lb/ft³, g/mL and 14 density units. Instant results with customizable decimal precision for science and engineering.

Convert GPS coordinates between Decimal Degrees, DMS, DDM, and UTM. See all four formats at once, preview on an interactive map, and copy any result.

Convert between degrees, radians, gradians, arc minutes, arc seconds, and other angle units. Instant results for math, physics, and navigation.