class Time

def find_zone(time_zone)

Time.find_zone "NOT-A-TIMEZONE" # => nil
Time.find_zone "America/New_York" # => #

Returns +nil+ for invalid time zones.
Accepts the time zone in any format supported by Time.zone=.
Returns a TimeZone instance matching the time zone provided. 
def find_zone(time_zone)
  find_zone!(time_zone) rescue nil
end