My gut-reaction to the title was to assume (based on the negative connotation to "time bomb") that you had some code that was permissively-licensed (something u

My gut-reaction to the title was to assume (based on the negative connotation to "time bomb") that you had some code that was permissively-licensed (something user-friendly like MIT or BSD), and then when the bomb "goes off", it switched to GPL, rendering it unusable in most commercial software.