If it truly is 1-testosterone cypionate, your source is wrong.
The half life of a Anabolic Androgenic Steroids (AAS) is determined by the ester that is attached to it - in this case cypionate. If you look at the insert for testosterone cypionate here (
http://www.mesomorphosis.com/downloads/testosterone-cypionate-pi.pdf), you'll see that they list the half life as 8 days.
A general rule of thumb to keep drug levels fairly even is take a dose every half half-life i.e. every 4 days for cypionate.