Test for timestamp parsing in metar.lua library

metar-timezone-test.lua

-- This is a code to test timestamp parsing in metar.lua library[1].
-- The original version (up to d99521d5) failed because mktime(3)
-- and os.date() expect local time as input.
--
-- [1] https://github.com/steelman/metar
function print_now(now)
   print (string.format('now => %d', now))
   print (string.format("local: %s",os.date('%Y-%m-%d %H:%M:%S', now)))
   print (string.format("UTC:   %s",os.date('!%Y-%m-%d %H:%M:%S', now)))
end

time = os.time()
print_now(time)

print ('---')

require ('metar')
m = metar.new('FOOO')
date = os.date('!*t', time)
s = string.format('FOOO %02d%02d%02dZ', date.day, date.hour, date.min)
d = m:_parse_metar_string(s)
print_now(d.timestamp)