January 13, 2020 (Monday) to January 19, 2020 (Sunday)
Week 3 of 2020 runs from January 13, 2020 (Monday) to January 19, 2020 (Sunday). This is the 3th week of the year according to the ISO 8601 standard, in which weeks start on Monday.
Jan 13 is a Monday. It is the first day of Week 3 of 2020.
Jan 19 is a Sunday. It is the last day of Week 3 of 2020.
Jan 13 is in Week 3 of 2020 according to ISO 8601.
Jan 19 is in Week 3 of 2020 according to ISO 8601.
Week 3 of 2020 runs from January 13, 2020 to January 19, 2020.
Week 3 of 2020 starts on January 13, 2020, the 13th day of 2020.
Yes, all 7 days of Week 3 of 2020 fall within 2020.
2020 has 53 weeks according to ISO 8601.