dayOfWeek property
The day of week, when the window starts. Possible string values are:
- "DAY_OF_WEEK_UNSPECIFIED" : The day of the week is unspecified.
 - "MONDAY" : Monday
 - "TUESDAY" : Tuesday
 - "WEDNESDAY" : Wednesday
 - "THURSDAY" : Thursday
 - "FRIDAY" : Friday
 - "SATURDAY" : Saturday
 - "SUNDAY" : Sunday
 
Implementation
core.String? dayOfWeek;