Items descended from the Timeline View note that have not $StartDate are placed in a column at the left side titled "NO DATE". Notes can be dragged to and from the timeline, in doing so setting or deleting their $StartDate.
If the Timeline note has $TimelineStart and/or $TimelineEnd set then any items in scope but with dates earlier or later than these limits are placed in a separate left-side column called "OUT OF RANGE". Events can be dragged from, but not to, this column.
These sidebar columns are only drawn if events of that type are present, otherwise they are not drawn.
If both columns are in use, the "NO DATE" column is drawn first (furthest left).
Within the columns, notes are placed within their respective timeline bands, if bands are in use.