No, the system time on your ARM device (or any other device AFAIK) is not relevant to getting a GPS fix.
Your GPS receiver should output UTC time. In general, GPS time is accurate to within 40 nanoseconds. The receiver performs two sets of calculations to deliver UTC time:
- The receiver synchronizes its internal clock with the extremely accurate atomic clocks in each of the GPS satellites. By synchronizing with multiple satellites, the receiver's effective timing accuracy is almost the same as the atomic clocks.
- Because the GPS satellites operate on GPS Time which does not include leap-seconds, the receiver must add these leap-seconds to GPS Time to get UTC.
Note that UTC time is the same everywhere in the world. Your local time is offset from UTC, typically based on your geographic location and whether or not some form of Daylight Savings Time is in effect. This is a simple addition or subtraction which is performed by your system. But it does not feed back into the receiver's calculations. The receiver doesn't care about anything except UTC. And as explained here, GMT is a time zone tied to certain geographic locations, whereas UTC is a time standard.
I can only guess as to why your system is having difficulty getting a fix. In my personal experience, weak signals are typically the culprit. Weak signals can result from any of several causes; e.g.:
antenna not mounted or connected properly to the receiver,
physical obstructions that attenuate the GPS signals (e.g. being indoors, perhaps in a basement not near a window)
using an improper antenna (many GPS receivers employ "active" antennas, and simply do not function well without them)
All I can suggest is trying to move your receiver & antenna to a different location (out-of-doors?) & checking to see if that improves acquisition time, and double-checking your receiver manufacturer's specs to ensure you have the proper antenna.