The traffic is way lower on Sunday with almost no one after 4:30 or so. All the shops should be open from 12 to 5 on Sunday and 10 am to 9 pm Monday through Saturday. Tax season has not affected the traffic times just the amounts of traffic dusting the busy times.
Shops usually close early due to the majority of people being LDS and Christian. Most are usually closed completely or open for a few hours. They can also close early Monday for Family Night.
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