Need to add a holiday date in display warning message when employee applying absence

Summary:

We have a requirement in absence, that when employee apply absences of PTO it should show a warning message with holiday dates, if any of the public holiday falls with in the duration

Content (please ensure you mask any confidential information):

If PTO is applied from 12/20 to 12/28 and Christmas day falls in 12/25. So it should a warning message with dates of christmas day.

How to add dates in warning messages in fast formula or manage messages.

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