How to Use the Stargazing Best Time Calculator
Stargazing works best once the sky is fully dark and moonlight is minimal. Enter tonight's sunset time, the moon's brightness (illumination percentage), and the light pollution level at your site to get a recommended start time, a sky quality rating, and how long a viewing window you can realistically expect.
The start time is estimated from the end of astronomical twilight after sunset, when the sky reaches true darkness. If moon brightness is above 70%, faint stars and the Milky Way are largely washed out, so the recommended window is shorter. Below 40% brightness, you can typically enjoy up to five hours of solid viewing.
Light pollution has a major impact on your rating. The same clear night might show only a handful of bright stars in a city, but reveal the full Milky Way in a remote location. Checking the light pollution level before choosing a campsite can help you plan a better stargazing trip.
Frequently Asked Questions
Even above 70% moon illumination, dim stars and the Milky Way are washed out, but bright first- and second-magnitude stars and planets remain visible. Narrow your viewing window and focus on those.
Dense city areas with lots of streetlights count as City, suburban edges as Suburb, campsites 30+ minutes from town as Rural, and remote mountains or coastlines with almost no artificial light as Remote.