For your easy reference, the following is a list of weeks and years with their corresponding date:
20 Sept 2015 – 25th Sunday in Ordinary Time Year B
21 Sept 2015 – Saint Matthew, Apostle, Evangelist – Feast
22 Sept 2015 – Tuesday of Week 25 Year 1
23 Sept 2015 – Wednesday of Week 25 Year 1
24 Sept 2015 – Thursday of Week 25 Year 1
25 Sept 2015 – Friday of Week 25 Year 1