zone_to_diff

# File lib/date/format.rb, line 1238
 def zone_to_diff(zone) # :nodoc:
 zone = zone.downcase
 if zone.sub!(/\s+(standard|daylight)\s+time\z/, '')
 dst = 1ドル == 'daylight'
 else
 dst = zone.sub!(/\s+dst\z/, '')
 end
 if Format::ZONES.include?(zone)
 offset = Format::ZONES[zone]
 offset += 3600 if dst
 elsif zone.sub!(/\A(?:gmt|utc?)?([-+])/, '')
 sign = 1ドル
 if zone.include?(':')
 hour, min, sec, = zone.split(':')
 elsif zone.include?(',') || zone.include?('.')
 hour, fr, = zone.split(/[,.]/)
 min = Rational(fr.to_i, 10**fr.size) * 60
 else
 case zone.size
 when 3
 hour = zone[0,1]
 min = zone[1,2]
 else
 hour = zone[0,2]
 min = zone[2,2]
 sec = zone[4,2]
 end
 end
 offset = hour.to_i * 3600 + min.to_i * 60 + sec.to_i
 offset *= -1 if sign == '-'
 end
 offset
 end