Estimates of hours for specific types of businesses are below. For exact hours, call before you go.
Offices and Small Businesses: 8:00 am or 9 am to 5:00 pm or 6 pm
Grocery Stores: 6:00 am or 7 am to 12:00 am (Midnight)
Malls: Monday – Saturday 10:00 am – 9:00 pm, Sundays 12:00 pm – 6:00 pm.
Most states and cities in the US charge an extra amount for certain items you purchase. The amount varies by state and city as well as the items subject to tax. In Albuquerque a 6.875% tax is charged for all items purchased except food and prescription drugs.
Check out http://www.tax.newmexico.gov/tax-holiday.aspx for information about the one weekend each year where there is no sales tax on many types of purchases including clothing, most computers, etc.
Returning Goods you don't want
Items can almost always be returned with a receipt, sometimes even when used or damaged. You will usually be asked why you are returning the item. If you do not have a receipt you may still be able to return the item for in-store credit.