APT Darkness Clock (APT DC) is a free app without ads, that calculates the suitable time for deep sky astrophotography or observing in selected night and location.
No matter what are imaging with - Canon EOS, Nikon, CCD or CMOS astro camera, APT has the right tool for planning, collimating, aligning, focusing, framing, plate-solving, controlling, imaging, synchronizing, scheduling, analyzing, monitoring and more.
This is the time between the evening astro twilight end, the morning astro twilight beginning and when the Moon is below the horizon.
The purpose of APT DC is to calculate what is the DSD Time duration and when this time starts/ends for selected night and location.
To image or observe a faint deep sky objects is needed to use the darkest time of the night.
It is a small sub-set of a full featured desktop application named APT - Astro Photography Tool.
APT is like Swiss army knife for your astro imaging sessions.
In APT that time is named DSD Time - Deep Sky Darkness Time.
It is possible to use the current location or one of three other stored observing sites.