Yes, guests at Disneyland California are allowed to leave the park and come back on the same day. When you enter the park, you will receive a hand stamp or have your ticket scanned, which allows you to exit and re-enter as many times as you'd like during operating hours. This flexibility is convenient for guests who may want to take a break, have a meal outside the park, or return to their hotel for a rest before continuing their Disneyland adventure. Just make sure to keep your ticket or hand stamp handy for re-entry, and enjoy the freedom to explore both inside and outside the park throughout the day.