To log this challenge, you must have found at least 50 caches on Fridays. Any Fridays, any caches. There are no restrictions on difficulty, terrain, cache type, location, or anything else. Just get outside and find 50 caches this Friday or any Friday/s, past, present, or future. You can find the cache and sign the log any day of the week.
To see if you qualify, use the checker:
To demonstrate that you qualify, just copy the sample log provided by the checker and include it with your log. Mine is posted as a note to show that I meet the challenge requirements. (It's not necessary to include your full list of qualifiers.)
Alternatively, you can message me with a list of your qualifying finds.
The cache is a small snap lock container hidden just off the Ridge Trail in Santa Rosa Open Space. Parking is at Belgatos Park. The trail is a little steep, but not too bad. 
Trail hours are 7 a.m. to sunset. Belgatos Park is open from 8 a.m. until one-half hour after sunset. Happy hunting!
Congrats to KendraH on the FTF!