Forgive the ignorant question, but is there an easy way to tell from these lists which trains stop at Harringay and Hornsey?
The following services all call at Hornsey and Harringay, basically pretty much anything heading to Hertford stops at those stations while Welwyn GC doesn't
Tad stupid as Hertfords can run insulated between Finsbury Park and Stevenage and leave the WGC services to pick up those calls as they already have 2tph that only call at Hatfield and Potters Bar but also as WGC has 6tph to Finsbury Park off peak so should cut back the stoppers to 3tph as it used to be to allow the Hertfords to run fast between Finsbury Park and Alexandra Palace.
HE52 from Monday 15th April
2J21 07:02 Hertford North to Moorgate
2K43 08:54 Welwyn GC to Moorgate
2F64 12:10 Moorgate to Stevenage
2J83 13:28 Stevenage to Moorgate
2J38 18:03 Hertford North to Moorgate
2V41 19:00 Moorgate to Welwyn GC
2B56 20:55 Moorgate to Hertford North
2J73 22:16 Hertford North to Moorgate
2F76 23:30 Moorgate to Stevenage
HE57 from Tuesday 16th April
2J01 04:22 Stevenage to Kings Cross
2F01 05:21 Kings Cross to Stevenage
2J17 06:28 Stevenage to Moorgate
2F19 07:40 Moorgate to Watton-at-Stone
2J47 09:07 Watton-at-Stone to Moorgate
2F68 12:40 Moorgate to Watton-at-Stone
2J87 14:11 Watton-at-Stone to Moorgate
2K21 16:32 Welwyn GC to Moorgate
2B45 19:25 Moorgate to Hertford North
2J59 20:30 Hertford North to Moorgate
2V61 21:30 Moorgate to Welwyn GC
Hope that helps?