From FIXwiki

FIX Message Component ComplexEventTimes

FIX Specification	Type	First introduced	Deprecated
Common	ImplicitBlockRepeating	FIX.5.0SP1

The ComplexEventTime component is nested within the ComplexEventDate in order to further qualify any dates placed on the event and is used to specify time ranges for which a complex event is effective. It is always provided within the context of start and end dates. The time range is assumed to be in effect for the entirety of the date or date range specified.

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Notes

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