Sidereal Time App

Sidereal helps astronomers, telescope users, and night-sky observers track Local Sidereal Time quickly and reliably.

Use Sidereal to view the current local sidereal time, calculate sidereal time manually from longitude, search locations, and plan ahead with future sidereal time tools. You can also create scheduled alerts so you never miss an important observing window.

Features:

View current Local Sidereal Time
Calculate sidereal time manually from longitude
Search by city or location
Use decimal or DMS longitude entry
Schedule sidereal alerts and reminders
Export upcoming alerts to your calendar
Browse future sidereal times for planning
Choose light, dark, or night-vision display modes
Sidereal is designed to be fast, practical, and easy to use in the field, whether you are setting up for imaging, aligning a mount, or planning an observing session.