World clocks and calculators
Clocks use your device clock and the browser’s IANA time-zone rules. Date arithmetic counts calendar dates, independently of daylight saving. Business days are Monday to Friday, optionally excluding listed public holidays. Timers save their state in this browser; they do not run an alarm service when your device is asleep.
Public holidays
We calculate holidays using date-holidays, an open-source project with country, state and regional rules. We display entries classified as public holidays, including substitute dates. Choosing “National holidays only” excludes additional state and local holidays. This is a planning calendar: new government announcements, one-off closures and moon-sighting decisions may not yet be reflected. Confirm travel and workplace plans with the appropriate authority.
Software: ISC licence. Holiday definitions and our generated holiday-calendar data: CC BY-SA 3.0. We calculate dates and select public holidays from the supplied rules. Full date-holidays licence and source attributions.
Weather
Forecasts are provided by MET Norway Locationforecast under CC BY 4.0. We summarise the forecast, convert wind speed to km/h, optionally convert temperatures to Fahrenheit, and group time steps into local calendar days. Daily ranges represent available forecast samples; today and the final day can be incomplete. The model update time is displayed. Forecasts are not observed conditions or an official warning service.
Worldwide tides
Open Waters calculates predictions using its Neaps harmonic engine and an international station database. The provider’s coverage page lists more than 6,000 stations across 126 countries. Search results identify each station’s country and region; coverage is not continuous along every coast.
Sources include NOAA and TICON-4. Each result shows its station source, source licence, gauge coordinates, harmonic observation period when available, height reference and time zone. Source data are used to calculate, plot and round predictions. We do not change the source station data. NOAA data are public domain; TICON data carry the licence linked with the station.
Heights are in metres relative to the named datum, such as LAT (lowest astronomical tide) or MLLW (mean lower low water). A harbour prediction must not be treated as the exact tide at a distant beach. Harmonic predictions omit storm surge and unusual meteorological effects. These tools are not for navigation or assessing safe access to coastal crossings.
Sun, Moon and space
Sunrise, sunset, twilight, Moon phases, planetary positions, seasons and eclipse times are calculated with Astronomy Engine by Don Cross (MIT). The observer is assumed to be at sea level, with an unobstructed horizon. Planet positions use 8 pm in the selected location; Moon illumination uses local noon. Global eclipse dates do not imply that an eclipse is visible locally.
For further reading, we link to NASA skywatching and NASA eclipse resources. Never observe the Sun without appropriate solar viewing protection.
Location search
Location names and coordinates come from Photon, operated by komoot, using © OpenStreetMap contributors data (ODbL). Time zones are estimated from coordinates using tz-lookup and can be approximate near boundaries. Select a specific town and check the displayed zone.
Availability
External data are cached to reduce repeated requests. A service outage produces an error message and a retry option; it is never replaced with invented readings. WhatTimeHere is an independent site and is not endorsed by these data providers.