The peak signal is quite brief, and occurs at much the same time every day, currently at about 19:25UT from north Wales.
Looking at DX Atlas, which is set to show the terminator and grey line to the end of Astronomical Twilight, it's very clear that the peak signal from Wales to DP0GVN happens when the path is almost entirely along the grey line sector. By the time DP0GVN is in its own greyline, Wales has gone into darkness, and propagation is much weaker, by roughly 10-15dB, and fails entirely by 20:30-21:00UT.
Over the next month, the path will become increasingly aligned along the evening greyline, as we pass into the Equinox. It will be interesting to see the expected lengthening of duration of peak signal.
In the morning, despite a better alignment of the greyline between stations, the strength of ionisation is not sufficient to sustain propagation before or around sunrise.
|Path from Wales to DP0GVN at typical peak signal reception time (19:25UT here)|