class Chronic::Time

def self.could_be_hour?(hour)

Checks if given number could be hour 
def self.could_be_hour?(hour)
  hour >= 0 && hour <= 24
end

def self.could_be_minute?(minute)

Checks if given number could be minute 
def self.could_be_minute?(minute)
  minute >= 0 && minute <= 60
end

def self.could_be_second?(second)

Checks if given number could be second 
def self.could_be_second?(second)
  second >= 0 && second <= 60
end

def self.could_be_subsecond?(subsecond)

Checks if given number could be subsecond 
def self.could_be_subsecond?(subsecond)
  subsecond >= 0 && subsecond <= 999999
end

def self.normalize_offset(offset)

normalize offset in seconds to offset as string +mm:ss or -mm:ss 
def self.normalize_offset(offset)
  return offset if offset.is_a?(String)
  offset = Chronic.time_class.now.to_time.utc_offset unless offset # get current system's UTC offset if offset is nil
  sign = '+'
  sign = '-' if offset < 0
  hours = (offset.abs / 3600).to_i.to_s.rjust(2,'0')
  minutes = (offset.abs % 3600).to_s.rjust(2,'0')
  sign + hours + minutes
end