Hi, that weekend was free, ans pretty much are open 7 days a week.
This year's Free Museum day was February 3. Otherwise, you can enter the Museum free every first Tuesday of the Month (except July and August), and every Tuesday in September. We recommend reserving tickets in advance to guarantee Museum entry and to skip the line, because of high attendance on these days. Additionally, L.A. County residents receive free Museum admission Monday through Friday from 3 - 5 pm with a valid ID or utility bill the day of your visit. You can find all of the information on our official site at nhm.org.
The first tuesday each month, exceptualy May and June
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