Way change of date may be expressed (6)
I believe the answer is:
stated
'be expressed' is the definition.
(similar in meaning)
'way change of date' is the wordplay.
'way' becomes 'st' (abbreviation for street).
'change of' indicates anagramming the letters (the letter order is changed).
'date' with letters rearranged gives 'ated'.
'st'+'ated'='STATED'
'may' acts as a link.
(Other definitions for stated that I've seen before include "Set forth (in words)" , "Close-fitting; drunk" , "Declared as fact" , "Definitely expressed" , "Asserted, affirmed" .)