Around 5:15 am PA Lottery is up and can sell numbers tickets. However, checking / redemption of any tickets, including instants, doesn't start until around 6 am.
On many (maybe all?) days, all numbers ticket sales close at 10:45 pm. Not sure if they resume anytime afterwards. Furthermore, not sure if this is a recent change or something PA Lottery has long done, but didn't notice. I've purchased tickets well into the 11 pm hour in the distant past. Regardless, all sales and redemption end at approx midnight.
Instant tickets may be purchased anytime on self-service terminals, but beware around 4 am +/-, the machine may reboot with no warning. Player won't lose any money, but may be forced to wait upwards of 10 minutes for the reboot sequence to complete.
As for raffle countdown, sales are slower than I would have imagine. I was figuring near 400,000, but it appears sales will come in around 350,000. The terminal screens don't show any countdown, but simply say "Buy!" in large print. Never seen any PA raffle go to the last day with no countdown.
As of now, I have 3 tickets, which, assuming a tad over 350,000 tickets sold, works out to 1 in 20 combined odds (3 plays) of winning $100+. Not getting my hopes up, since I've played with many times that in the past and still wiped out, but hoping this time is different. Especially, being this could be the last PA raffle of this kind.