'Method to return the date for a log line.
This uses a custom version of strptime, using the named groups
from the instances `pattern` property.
Parameters
line : str
Log line, of which the date should be extracted from.
default_tz: optionally used to correct timezone
Returns
(float, str)
Tuple containing a Unix timestamp, and the string of the date
which was matched and in turned used to calculated the timestamp.'

def getDate(self, line, dateMatch=None, default_tz=None):

    if (not dateMatch):
        dateMatch = self.matchDate(line)
    if dateMatch:
        return (reGroupDictStrptime(dateMatch.groupdict(), default_tz=default_tz), dateMatch)
