MA, Why not just implement an event timer, where you press it to start, it then joins u to the event, and press it to stop, where it discons u from the event, all other time ingame is not attached to your event time, and any event mob killed outside of being 'in' the event doesnt count either.
After 6 hours in any 24hr period the timer auto disconnects you from event.
When i log in, im at cp. I gotta get rid of all my stuff, come down and change armour/plates etc, ammo up, repair, get to preffered hunting ground. That could take~30 minutes. so then, i got 5hrs 30 minutes to hunt, whereas others, more fortunate with the timing, are already sorting this now so at 18:00UTC they can log in the middle of their hunting ground, fully equipped with enough ammo for 6 hrs*cough, and are already 30 mins better off than me in that days hunt before a mob has even been shot.