pablo,
I don't know if there are set days, but I have seen the Erie yard job down on the Lake front on Mondays and Thursdays, when I have visited the library. They seem to arrive anywhere from 10 A.M. to 2 or 3 in the afternoon, more often then not, in the morning. It is an interesting operation. They'll switch the yard, crossing back and forth over Holland St., then head to the GAF plant,west of State St.[not far from the Lansdowne car ferry,with the Milwaukee Skytops on it -it just sank this past week,btw,but is being raised up again ]. Then head back east, sometimes crossing the bayfront highway to head down to the Marine terminal. If your lucky, you can also catch them crossing [backing] the bayfront highway to deliver coal cars to the coke plant. It's always interesting watching them inter-act with the highway traffic! Seems kind of close at times. I once asked the Conductor, who was flagging Holland St. ,why they didn't put gates there and he said people would just run into them ! Probably would.