I'd just like to put in a word for those station clocks which are widely known to be consistently wrong.
In Edinburgh, the clock above Waverley on the Balmoral Hotel (a.k.a. North British Hotel) runs a few minutes fast, by tradition. The expectation is that this assists passengers in arriving in time for their train. The clock is large enough to be read from almost a mile away. (Strictly, the clock is not on railway property. By the time any passenger has negotiated the out-of action escalators or the barred ramps, and additional minutes are lost anyway).
In Newcastle, the clocks above the entrance to the portico runs a few minutes slow. This has been the case since GNER days though appeared to have been corrected over recent months. I spoke to the Properties Manager at one time about it and although I can't recall the conversation, it was not something that was going to be rectified for some time (and it wasn't). It doesn't appear to be the cause of passengers arriving late at the station.