FACTORY CALENDAR-Transport

Hi ,

I am facing one issue while transporting the factory calendar from development client to quality.

While transporting system is giving following messege-

"All public holidays, public holiday and factory calendars will be tranported. All public holidays ,public holiday and factory calendars will first be deleted in the target system"

Can anybody suggest the reason/impact of this messege. Will it be any problem if I ignore the messege and transport the new factory calendar???

REgards,

Priti