官方解释 : f v( a/ n: m- Z3 O# K/ {http://www.stm.info/en/info/fares/transit-fares/monthly-cam + ~, @. R% A# E7 H' ]' E* Q5 w/ N o5 j5 B' _ g8 Z) Z
The transit fare is valid from the first to the last day of the month. 6 L3 \: f, M* e. A2 e# z0 r' M) V
Monthly fare cards are available on the 20th day of the preceding month at all points of sale. ) n- h, O% y; D( b: x" u