ggplot2：重塑数据以绘制每个X值的多个Y值

I have a data frame which contains 2 weeks of data that indicate how many passengers have been on a train each day. Each observation contains 3 values, the date, the number of passengers, and the day of the week. I want to compare the passengers on each day from the previous week to this week (Monday to Monday, Tusday to Tuesday etc). Here is the data:I have a data frame which contains 2 weeks of d