Add utc date time snippet

UltiSnips/all.snippets

@@ -24,14 +24,44 @@ def commentafter():
 	return ''
 
 import datetime
+import time
+
 def date():
 	return datetime.datetime.now().strftime('%B %d, %Y')
+
+class LocalTZ(datetime.tzinfo):
+	"""Query OS for local timezone offset."""
+
+	def __init__(self):
+		"""Initialize LocalTZ."""
+		datetime.tzinfo.__init__(self)
+		self._unixEpochOrdinal = datetime.datetime.utcfromtimestamp(
+			0).toordinal()
+
+	def dst(self, _):
+		return datetime.timedelta(0)
+
+	def utcoffset(self, dt):
+		t = ((dt.toordinal() - self._unixEpochOrdinal) * 86400 + dt.hour * 3600
+			 + dt.second + time.timezone)
+		utc = datetime.datetime(*time.gmtime(t)[:6])
+		local = datetime.datetime(*time.localtime(t)[:6])
+		return local - utc
+
+def utc():
+	value = datetime.datetime.strftime(
+		datetime.datetime.now(LocalTZ()), '%Y-%m-%dT%H:%M:%S%z')
+	return '%s:%s' % (value[:-2], value[-2:])
 endglobal
 
 snippet date "Today's date"
 `!p snip.rv=date()`
 endsnippet
 
+snippet utc "UTC date time now" i
+`!p snip.rv=utc()`
+endsnippet
+
 snippet todo "TODO commment"
 `!p snip.rv=commentbefore()`TODO${1/.+/(/}$1${1/.+/)/}: $0`!p snip.rv=commentafter()`
 endsnippet