I started at 17:00 UTC. I didn't pay tribute the first day. Instead the pattern went...

Day - Tribute
2 - 1 gold
3 - 1 gold
4 - 3 gold
5 - 3 gold
6 - 3 gold
7 - 4 gold 1 timer

However on day 3 the management page said my next tribute would be 1 gold and on day 6 is said my next tribute would be 3 gold.

So I'm never quite sure what my next tribute will really be. It does appear to be following a 3 day pattern though.

Also if you don't pay tribute on day 1, people starting at 7:31 UTC have a small advantage over those starting later in the day, and both have a
bigger advantage over people starting just before 7:15 when you would pay the tribute immediately.

The "next tribute" information is my real problem though.