It's not that, it's a Saturday morning only nonstops:
Code:
flight | op | orig | dest | eqp | departs | from | to | days
--------+----+------+------+-----+----------+------------+------------+---------
UA4843 | ZW | IAD | ORD | CRJ | 08:15:00 | 2018-03-10 | 2018-03-10 | S
UA4845 | ZW | IAD | ORD | CRJ | 11:39:00 | 2018-03-10 | 2018-03-10 | S
UA4843 | ZW | IAD | ORD | CRJ | 08:15:00 | 2018-03-17 | 2018-03-24 | S
UA4845 | ZW | IAD | ORD | CRJ | 11:39:00 | 2018-03-17 | 2018-04-07 | S
UA4843 | ZW | IAD | ORD | CRJ | 08:15:00 | 2018-03-31 | 2018-04-07 | S
UA3767 | ZW | IAD | ORD | CRJ | 08:12:00 | 2018-04-14 | 2018-04-21 | S