When Does the Zaishen Monthly Tonic Change?

I saved up all my Zaishen keys because I thought, if I get an everlasting tonic, I'd like to get the Phantasmal one. Life got busy and I forgot, and here it is May 30th and I have about 200 Z-keys to blow through. When does it switch from Phantasmal to Automatonic? Does it go by the calendar, Pacific Time? Giving me until 11:59PM on the 31st? (Not that I'd wait that long.)

Simply said: yes, it goes by calender in PST and thus gives you until 11:59 pm PST on the 31st to ENTER the isle of the nameless. The rewards stay the same as long as you don't leave the area (don't count on that to open the chest for the phantasmal tonic though, a dc always happens at the wrong times.).

Do take note that if you are using the keys just for that tonic, it would be cheaper to sell the keys and buy it.

Thanks so much for the detailed info. Now I can actually take some time to clear out my inventory before I get at the chest later today.

Heh. Sage advice! I know the drop rate is poor, but I'll be opening for my HoM statue. A friend did the same and got an EL Skeletonic. If I should have the same luck, I figured I'd at least want to get a tonic I like.

You could also look for a key service on this forum many give you 3x the drops so with your 200 you would have 600 drops increasing your chances tremendously just a thought. that is what i did with mine.

This still has 2 problems with it: 1. You won't get title points (he stated he was going for HoM).
2. It would still cost alot more then just selling a few keys and buying the tonic unless you're very lucky. If you assume 5k/key and 300k/tonic: to break even with tripple drops they would need to have a everlasting tonic drop in the first 60 keys given to the service as 300/5=60 and 60x3=180.
These prices are extremely unlikely (nearly impossible) to find in the current market, 5k/key is too low and 300k/tonic is too high. I used these values to compensate for other drops, assuming you get atleast a few reasonable gold items (again, unlikely). The actual market prices would give less chances to get a tonic before you make a loss.

Telling someone to go for a tripple drop service is bad advice from a financial point of view. The chance you get something increases but the chance you make a loss is still larger then making a profit. The only reason the keys are pricy is the title, in turn this makes the drops worthless in comparison to the keys instead of nearly breaking even.
This is the reason those services are available, they wouldn't do it if they had a large chance to have a profit from those keys. It becomes cheaper for the one doing the service this way as someone is basically sharing his losses. They do not do it out of charity.