According to the Rede Expressos site there are two daily departures from Lisbon Sete Rios Bus Station to Nazare at 12:00 and 14:00. Transit times are 1hr50min. First return in the mornings is a daily departure at 06:50.
I have posted the relevant Rede - Expressos timetable extract here:
http://scr.bi/bmuglz
To get from Lisbon Airport to Lisbon Sete Rios Long distance Coach Station take the following bus which leaves from outside the Arrivals hall:
(Aeroshuttle - Copy of note from Lisbon Airport website.) Aeroshuttle (CARRIS Nº96) - Available everyday, every 30 minutes between 7am and 11pm, the aeroshuttle connects Gare Oriente - Airport - Entrecampos - Sete Rios Coach Station - Praça de Espanha.
Tickets (3,50€) can be purchased onboard and also in the Tourism Office at arrivals (public area).
Tel. +351 213 582 334)
Transit time about 20 minutes.
