there's an RTC-module (Real-Time-Clock) which you could use, but any 32-bit timer will do better. Use as the clock input for the timer a 1MHz clock, set the period to 360000000 and you get a TC of 6 minutes with a resolution of 1µs. When using an interrupt to count the 6 minutes, have a look at the CY_ISR_PROTO(), CY_ISR() (both to find in the System Reference Manual under "Help->Documentation" in Creator) and Isr_Startex() (Datasheet of Isr). I just posted a similar example for Neha, have a look at that project.
Thanks again Bob!