From National Rail:
The Southern service on Saturday wiII therefore be:
Forest Hill to London Bridge (3 minutes later from Honor Oak Park)
13 & 43 minutes past each hour from 0643 to 2313
London Bridge to Forest Hill
10 & 40 minutes past each hour from 0710 to 2340 then 0020 and 0035
There will be the usual 4 trains per hour on Sunday as the London Bridge - Crystal Palace & v.v. service which only operates on Sundays is unaffected by the engineering work.