Get day name from a valid date. Invalid dates will return blanks.
weekdayname DATE
weekdayname 20210601
Tuesday
weekdayname 3214132
''
Input Result
.→-----------------------.
| .→-------. .→--------. |
| ↓20210601| ↓Tuesday | |
| |20210602| |Wednesday| |
| |20210603| |Thursday | |
| | 1324| | | |
| |20210605| |Saturday | |
| |20210606| |Sunday | |
| |20210607| |Monday | |
| '~-------' '---------' |
'∊-----------------------'