Behaviour when no broadcast date is known

[canihavesomecoffee]

Hello,

first of all I'd like to thank you for this nice maintained PHP library for accessing theTVDB.

I'm wondering however, if the current behaviour for creating a DateTime object based on the FirstAired field for episodes is correct. If there is a FirstAired, it creates the DateTime object just fine, but in my case I have a couple of series where the FirstAired field in xml is just empty...

This results in the DateTime object being initialized at the current time, which makes it rather annoying to compare against a previously stored value...

So my question is if this shouldn't be changed to something which indicates that there is no known value for this yet.

An example of the XML which doesn't contain an FirstAired element:

<?xml version="1.0" encoding="UTF-8" ?>
<Data>
  <Series>
    <id>300472</id>
    <Actors>Snipped for brevity</Actors>
    <Airs_DayOfWeek></Airs_DayOfWeek>
    <Airs_Time></Airs_Time>
    <ContentRating></ContentRating>
    <FirstAired></FirstAired>
    <Genre>|Adventure|Drama|Fantasy|Horror|</Genre>
    <IMDB_ID>tt1316546</IMDB_ID>
    <Language>en</Language>
    <Network>AMC</Network>
    <NetworkID></NetworkID>
    <Overview>Snipped for brevity</Overview>
    <Rating></Rating>
    <RatingCount>0</RatingCount>
    <Runtime>40</Runtime>
    <SeriesID></SeriesID>
    <SeriesName>Preacher</SeriesName>
    <Status>Continuing</Status>
    <added>2015-09-09 13:23:34</added>
    <addedBy>417533</addedBy>
    <banner>graphical/300472-g2.jpg</banner>
    <fanart>fanart/original/300472-1.jpg</fanart>
    <lastupdated>1452903959</lastupdated>
    <poster>posters/300472-1.jpg</poster>
    <tms_wanted_old>0</tms_wanted_old>
    <zap2it_id></zap2it_id>
  </Series>
</Data>

[Moinax]

That's a good idea, I merged your PR.

Regards,