Well, Generally the best day trips from Barcelona for the weekends are: Half Day Trip to Montserrat From Barcelona , Girona and Costa Brava Tour From Barcelona and a tour of Visit Three Countries In One Day ( Spain , France and Andorra )
For example, we are not recommending a Half Day Trip to Montserrat From Barcelona , on Sundays at mid-day departure (10:00 am) . because usually, Montserrat is one of the favorite destinations for the locals to go, lots of people from Barcelona and the area around are coming there for the weekend to enjoy their day in the beautiful mountain of Montserrat, visiting the monastery, attending choir performances or a little bit more active for hiking or biking.