Add the timezone of the payout date on your website (presumably midnight Phoenix, AZ, GMT --6/7).
1
vote

-
AdminAlex (CEO / Founder, GroupFabric) commented
Internally the website uses UTC, which is then converted to your local time when shown - that said, the pool can issue payouts on 1-3 days before that date because it depends on the level of Bitcoin network congestion and network fee optimization.