I have created a GPS time utility program that runs on a PC as a DOS console application. It performs the following:

(1) Given the month/day/year outputs the Julian day, day of year and GPS week number

(2) Given the Julian Day, outputs the date, day of year, and GPS week number

(3) Given hours:mins:secs outputs the z-count and day of week

(4) Given seconds of the week, outputs z-count, hour:min:secs,  and day

(5) Given z-count outputs seconds of week and day, hour, min, secs

(6) Given week and seconds of week outputs hour, mins, sec, year, day of year

(7) Provides a handy z-count summary by day and hour

This program is useful when doing development and testing, especially if you have a mixed-bag of receivers that have different requirements for time I/O. The program is very modestly priced.