toRelativeTime method
Relative string like 'Today', 'Yesterday', '2 days ago'
Implementation
String toRelativeTime() {
final now = DateTime.now().toUtc().add(App.timezone.offset);
final local = toJBTimezone();
final diff = now.difference(local);
if (diff.inDays == 0) return "Today";
if (diff.inDays == 1) return "Yesterday";
if (diff.inDays < 7) return "${diff.inDays} days ago";
return toShortDate();
}