According to the search results, USPS delivers mail from Monday to Saturday in ordinary circumstances, and deliveries are made up until 5 PM. However, the delivery time of day for a specific address may vary according to different factors. In some situations, deliveries may be made after 5 PM, especially if traffic delays or bad weather has slowed a mail carrier down. If this happens, the mail will be delivered the following day. USPS also has “business hours” available Monday through Saturday at most postal office locations. USPS does not deliver on Sundays throughout the year. USPS also does not operate on the following holidays:

• Christmas Day (25th of December, federal holiday)
• Thanksgiving Day (Fourth Thursday of November, federal holiday)
• New Years Day (1st of January)
• Memorial Day (fourth Monday of May)
• Veterans Day (11th of November)

However, some mail types such as Priority Mail & Priority Mail Express items might be delivered on Saturdays.