From National Rail website:
Rail replacement bus services calling at all stations between New Cross Gate and West Croydon and are scheduled to operate in both directions as follows:
From Forest Hill towards New Cross Gate every 10 minutes from 0540 to 0120 (5 minutes later from Honor Oak Park)
From Forest Hill towards West Croydon every 10 minutes from 0553 to 0113 (5 minutes earlier from Honor Oak Park)
From New Cross Gate towards Forest Hill every 10 minutes from 0540 to 0100
SATURDAY UPDATE: As per comments from @fran below (thanks Fran) the buses to New Cross Gate are getting severely delayed due to the traffic queuing for the petrol station in Brockley which will probably have a knock on effect on all the replacement services!
For those living on the borders of SE23 who have to travel today you might want to consider other stations in the area that you’re able to get to without relying on buses! E.g. Catford Bridge for trains to London Bridge (4 per hour), Cannon Street (2 per hour) and Charing Cross (2 per hour), Crofton Park, Nunhead and Peckham Rye for services to Elephant & Castle and Blackfriars (2 per hour) or Penge East and Sydenham Hill for services to Brixton and Victoria. There are also 2 trains per hour from Crystal Palace to London Bridge via Tulse Hill which takes 28 minutes!
From Forest Hill towards New Cross Gate: every 10 minutes from 0630 to 0020 (5 minutes later from Honor Oak Park)
From Forest Hill towards West Croydon every 10 minutes from 0653 to 0003 (5 minutes earlier from Honor Oak Park)
From New Cross Gate towards Forest Hill every 10 minutes from 0640 to 2350
For stations towards New Cross Gate the buses will use Bus Stop E on Dartmouth Road (by Stanford Estates where 122 stops) and bus stop HB on Honor Oak Park
For stations towards West Croydon the buses will use bus stop B in London Road (by the Guava Kitchen) and bus stop HA on Honor Oak Park
From New Cross Gate the buses will use bus stop R in New Cross Road