timeAgo method
Returns a human-readable string representing how long ago this date was.
Implementation
String timeAgo() {
final Duration diff = DateTime.now().difference(this);
if (diff.inSeconds < 60) return '${diff.inSeconds} sec ago';
if (diff.inMinutes < 60) return '${diff.inMinutes} min ago';
if (diff.inHours < 24) return '${diff.inHours} hrs ago';
if (diff.inDays < 7) return '${diff.inDays} days ago';
if (diff.inDays < 30) return '${(diff.inDays / 7).floor()} weeks ago';
if (diff.inDays < 365) return '${(diff.inDays / 30).floor()} months ago';
return '${(diff.inDays / 365).floor()} years ago';
}