Webgrab Plus is an external XMLTV EPG source, so you are dependent on it to get the time offset from GMT correct. No doubt your PC and therefore MC know what time it is now, but the Offset included in the EPG data isn't correct. MC doesn't have an offset in its settings, because it uses the PC time information.
For example, this is a program in my EPG data.
<programme start="20180327110055 +1100" stop="20180327113100 +1100" channel="1">
<title>Cheers</title>
<desc>Diane looks to her friends for comfort when her cat dies, but everyone is too enthralled by a Celtics game to notice.</desc>
<category>Series - Comedy</category>
</programme>
Note the +1100, which means I am 11 hours ahead of GMT currently. I'm not using Webgrab Plus, but all XMLTV EPG data needs to include that offset.
You need to tell Webgrab Plus what the new offset is, or change its settings so that it collects that information automatically.