The first thing I would do is to add some serial print statements to the BLYNK_WRITE callbacks so that you know when they’ve been triggered, and can see what parameter values you are getting.
Also, the “V” in the virtual pin identifier is optional, so you could simply do:
#define ZONE_1_TIMER 10
This can be handy if ever you need to loop through a number if pins with a for statement.
You can also use the BLYNK_WRITE_DEFAULT() callback if you have multiple BLYNK_WRITE(vPin) callbacks that do very similar things.
Not really needed for this situation, but you might find it handy in future.
An example of how to do this is in this post:
Pete.