I have just released a GPS time source module that provides the UTC time and a one pulse per second (1PPS) pulse output for your projects requiring precise time or exact synchronization. It has a built-in antenna, which works great next to a window, though you can connect an external one if desired.
Transmission is through RS485, so distance is no problem if your application location has no clear view of the sky. Connection to the module is by a RJ45 plug, using readily available CAT5 cabling.
The UTC time is sent using the well-known NMEA sentences (GPGGA, GPGSA, GPGSV, GPRMC, GPVTG), and has the added benefit of bearing the current position and velocity information.
The 1PPS signal is of timing quality, and great for driving a GPS disciplined oscillator (GPSDO).
It is currently on sale through the end of the year!