Represents a date-level annotation — holidays, special hours, closures, notices.

Day markers are not events. They annotate the date itself rather than occupying a time slot. They appear as visual indicators on the day cell (background color, label, icon) and can span multiple days.

Use day markers for:

• Public holidays ("Christmas Day", "New Year")
• Special operating hours ("Winter hours: 10am-3pm")
• Office closures ("Office closed for renovation")
• Seasonal notices ("Peak season — limited availability")
• Custom date labels ("Payday", "Sprint 12 start")

Day markers can optionally override availability — e.g., a holiday marker with available: false blocks booking, while a "reduced hours" marker with custom availability windows allows booking within those reduced hours.

Examples

# Public holiday — fully closed
%DayMarker{
  id: "xmas",
  label: "Christmas Day",
  start_date: ~D[2026-12-25],
  end_date: ~D[2026-12-26],
  type: :holiday,
  color: "bg-error/20",
  icon: "🎄",
  available: false
}

# Reduced hours — bookable within modified schedule
%DayMarker{
  id: "winter-hours",
  label: "Winter Hours",
  start_date: ~D[2026-12-20],
  end_date: ~D[2027-01-05],
  type: :notice,
  color: "bg-info/10",
  description: "Reduced hours: 10am-3pm",
  availability: [
    %PhoenixLiveCalendar.Availability{
      days_of_week: [1, 2, 3, 4, 5],
      start_time: ~T[10:00:00],
      end_time: ~T[15:00:00]
    }
  ]
}

# Simple label
%DayMarker{
  id: "payday",
  label: "Payday",
  start_date: ~D[2026-04-15],
  type: :label,
  color: "bg-success/10"
}

# Heatmap tint — cell background only, no corner label chip
%DayMarker{
  id: "activity-2026-04-15",
  label: "42 minutes",
  start_date: ~D[2026-04-15],
  color: "bg-success/30",
  show_label: false
}

Styling

• color — cell background class. When set, it becomes the day cell's background (winning over the weekend/out-of-month tint; today/selected stay visible via an inset ring). When unset, the cell falls back to the type-based tint (:holiday/:closure/:notice/:season).
• text_color / class — applied to the corner label chip instead of the type-based chip colors. class is the chip background/extra classes, text_color the text class.
• show_label — set false (or label: nil) to render only the cell tint with no corner chip; ideal for heatmap-style markers.

All classes are the consumer's responsibility to make Tailwind-visible (complete class names, no interpolation).