Network rail signallers manipulate time

Another successful walk on the Kennet and Avon canal. Today from Bedwyn station to Pewsey station. We're trying to do it all by public transport; and returning from the quiet of Pewsey to the rush of Friday evening at Reading, I spotted this sign.

The 18:15 departure was at the platform... Of course it was resolved by a last minute platform alteration for the 18:13.