countytimezones: Convert UTC to Local Time for US Counties

countytimezones is an R package that inputs date-times in Coordinated Universal Time (UTC) and converts to a local date-time and local date for US counties, based on each county's Federal Information Processing Standard (FIPS) code. This work was supported in part by grants from the National Institute of Environmental Health Sciences (R00ES022631) and the National Science Foundation (1331399).