# module localtime -- Time conversions

import posix

epoch = 1970				# 1 jan 00:00:00, UCT
day0  = 4				# day 0 was a thursday

day_names = ('Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat')

month_names =               ('Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun')
month_names = month_names + ('Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec')

month_sizes = (31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31)

def isleap(year):
	return year % 4 = 0 and (year % 100 <> 0 or year % 400 = 0)

def gmtime(secs):			# decode time into UCT
	mins, secs = divmod(secs, 60)
	hours, mins = divmod(mins, 60)
	days, hours = divmod(hours, 24)
	wday = (day0 + days) % 7
	year = epoch
	lp = isleap(year)
	dpy = 365 + lp
	while days >= dpy:
		days = days - dpy
		year = year + 1
		lp = isleap(year)
		dpy = 365 + lp
	yday = days
	month = 0
	dpm = month_sizes[month] + (lp and month = 1)
	while days >= dpm:
		days = days - dpm
		month = month + 1
		dpm = month_sizes[month] + (lp and month = 1)
	return (year, month, days+1, hours, mins, secs, yday, wday)

def dd(x):
	s = `x`
	while len(s) < 2: s = '0' + s
	return s

def zd(x):
	s = `x`
	while len(s) < 2: s = ' ' + s
	return s

def format(year, month, days, hours, mins, secs, yday, wday):
	s = day_names[wday] + ' ' + zd(days) + ' ' + month_names[month] + ' '
	s = s + dd(hours) + ':' + dd(mins) + ':' + dd(secs)
	return s