General AI Tools
Parhélie
26d agoParhélie is a web‑app that calculates the exact solar altitude for any city worldwide and identifies the precise dates, down to the day and hour, when another city experiences the same sun position. It provides solar event data such as zeniths, solstices and equinoxes, covers 7,774 cities with populations over 80 000 across all continents, handles exact time‑zones and daylight‑saving automatically, and runs in a browser on iPhone, Android and computers without requiring App Store or Play Store installation. After a one‑time €0.99 purchase the app can be added to the home screen and works offline.
Exact solar position calculationCross‑city sun matchingSolar event identificationGlobal city coverageWeb‑based cross‑platform accessOne‑time purchase model
Key Capabilities
01
Exact solar position calculation
Uses NOAA solar algorithm with ≈0.1° precision to determine sun height for any location.
02
Cross‑city sun matching
Finds the exact date and hour when another city shares the same solar altitude as the selected city.
03
Solar event identification
Provides dates for zeniths, solstices and equinoxes for each city, including leap‑year handling.
04
Global city coverage
Supports 7,774 cities with >80 000 inhabitants, covering all continents with accurate time‑zone and DST data.
05
Web‑based cross‑platform access
Runs instantly in browsers on iPhone, Android and computers; can be added to the home screen and used offline.
06
One‑time purchase model
Available for a single payment of €0.99 with no subscription fees.
Use Cases
Expatriate nostalgiaDiscover when the sun in a new residence matches the sunlight of the hometown.People living far from their city of origin
Seasonal travel planningChoose travel dates when the destination’s light mirrors that of another location.Travelers seeking specific lighting conditions
Photography schedulingPlan shoots to capture lighting identical to a reference location.Photographers
Educational demonstrationTeach solar geometry by comparing sun positions across different cities.Teachers and students
Curiosity‑driven sky observationExplore unique solar coincidences for personal interest.General sky enthusiasts
Update History
Updated 26d ago▲ 0% mentionsProduct HuntWeb