Time diff NOT WORKING

Looking at the dates, my first thought was DST. DST in Europe originated in the First World War to aid in munitions manufacturing.

In Europe DST changes on the last Sunday in March and the last Sunday in October. It just so happens that this year the last Sunday is the 31st. The EU member states have voted to cease using DST but have yet to decide when this will happen - maybe on the last Sunday of October then they've an hour to decide if they like it and can switch it back again!