Page "Epoch (astronomy)" Paragraph 21
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Thus a particular coordinate system ( equinox and equator / ecliptic of a particular date, such as J2000. 0 ) could be used forever, but a set of osculating elements for a particular epoch may only be ( approximately ) valid for a rather limited time, because osculating elements such as those exampled above do not show the effect of future perturbations which will change the values of the elements.
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2.015 seconds.