Below is a list of Janesville CA zip codes. For your research we have also included Janesville Area Code, Time Zone, UTC and the local Lassen County FIPS Code. Each Janesville California zip code has a center Longitude / Latitude point (the Janesville center is -120.5240020752 / 40.296001434326). For your convenience we have also indicated if that zip code in Janesville observes Daylight Savings time.