Data Sources & Horological Standards
At TimeNumbers, accuracy is our highest priority. Every clock tick, timezone conversion, and astronomical calculation is anchored in globally recognized scientific and civil standards.
IANA Time Zone Database (tzdb)
Maintained by Paul Eggert and the international internet engineering community, the IANA tz database provides canonical historical and future daylight saving rules, leap second records, and civil time offsets worldwide.
NOAA Solar Ephemeris
Our sunrise, sunset, solar noon, and twilight calculations utilize the NOAA Solar Position Algorithm, factoring in the equation of time, solar declination, and atmospheric refraction for sub-minute accuracy.
Stratum-1 Atomic Synchronization
Client drift is benchmarked against primary Stratum-1 Network Time Protocol (NTP) servers synchronized with atomic frequency standards maintained by NIST, BIPM, and GPS constellations.
GeoNames Global Geocoding
City coordinates, administrative boundaries, populations, and country designations are cross-referenced with the open GeoNames geographical database for global geographic accuracy.
Explore Global Time & Related Directories
Quick access to international capitals, timezone offsets, chronometry tools, and horology guides