The Seiko caliber 5X53 is a solar powered quartz movement with GPS. The 5X53 is found in Seiko Astron GPS Solar Dual-Time models first introduced in 2018.
This calibre can set the time automatically using GPS and features a pointer day subdial at 3:00, date window at 4:30, dual time capability with day/night indication, as well as world time with 39 time zones.
Like most quartz movements, this caliber has a crystal oscillator vibrating at a frequency of 32,768 Hz. Seiko claims that the accuracy of this caliber is within +/-15 seconds per month – not including using the watch for automatic time setting via GPS.
A full charge will give 5X53 powered watches up to 6 months of power reserve. There is a power save function which will allow the watch to continue running for up to 2 years.
Note: This caliber listing is still being updated, but feel free to start discussions on it in the comments below…