Generally, you can enter Petra from around 6:00am until about 6:00pm in the summer, 4:00pm in the winter. As I mentioned above, entrance costs vary depending on how many days you're visiting and whether you're staying overnight. The official website breaks it down even more, including guide costs.

To truly experience the majesty of Petra without the overwhelming heat and crowds, you should aim to arrive at the Visitor Center right when it opens at 6:00 AM. Arriving at dawn allows you to walk through the Siq (the narrow gorge) in relative solitude and see the Treasury building bathed in the soft, early morning light before the large tour buses from Amman and Aqaba arrive around 9:00 AM. This early start is also crucial if you plan to hike to the Monastery (Ad Deir), as the 800-step climb is much more bearable in the morning cool than in the midday desert sun. If you are staying in Wadi Musa (the town adjacent to Petra), being among the first through the gates ensures a peaceful, spiritual experience. Alternatively, staying late until the park closes at sunset offers another quiet window, but the morning remains the gold standard for photographers and serious hikers alike.