Nowadays, train times somehow manage (12)
I believe the answer is:
administrate
'manage' is the definition.
(administrating is a kind of managing)
'nowadays train times somehow' is the wordplay.
'nowadays' becomes 'AD' (AD, Anno Domini, as opposed to BC, Before Christ).
'somehow' indicates an anagram.
'train'+'times'='traintimes'
'traintimes' with letters rearranged gives 'ministrate'.
'ad'+'ministrate'='ADMINISTRATE'
(Other definitions for administrate that I've seen before include "Organise (business)" , "direct" , "Manage - it's marinated (anag)" , "Run" .)