Radarr/frontend/src/Calendar/Day/DayOfWeek.css

.dayOfWeek {
  flex: 1 0 14.28%;
  background-color: var(--calendarBackgroudColor);
  text-align: center;
}

.isSingleDay {
  width: 100%;
}

.isToday {
  background-color: var(--calendarTodayBackgroundColor);
}