The 737 area code belongs to the state of Texas (TX) and some of the locations covered are Cedar Park, San Marcos and more:
|State||Larger cities in area code 737||Time Zone|
|Austin, Bastrop, Buda, Cedar Park, Elgin, Georgetown, Kyle, Leander, Lockhart, Pflugerville, Round Rock, San Marcos, Taylor
Current time is
|-- overlays area code 512 --|
Starting July 1, 2013 the Austin area and surrounding communities in Texas have a new area code overlaying existing NPA 512. The new 737 area code covers the same geographic area and all local calls must be dialed using 10 digits.
More info (PDF document)