While the timeline does have a built-in virtualization mechanism for its visual items, it does not have this mechanism for the models (non visuals) it works with. In your case, the timeline is trying to create 157 million models (one model for each second in the 5 year range).
We have this logged in our feedback portal
where you can vote and track its status.
As you see, the timeline does not support this specific case (large range and small intervals). We can only suggest that you implement some application-appropriate solution. For example, you can have one main
control that shows the whole range (a calendar or a timeline). The user will be allowed to select a range in this control and the information contained in this range can be shown in the secondary
timeline. The selection that the user can make in the main control must be limited to some maximum (say one week) so that you make sure that the secondary timeline does not have to create too many models.
Hope this information is helpful, let us know if you have other questions.
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