Pubs will serve alcohol from opening time at 12.30pm, as normal on St Patrick's Day, however there will be no off-licence sales in pubs, off licences and supermarkets until 4pm in city centre.
Licensed premises have agreed to the voluntary initiative, which was announced by the gardaí at the festival launch this morning.
Gardai confirmed the restricted area runs from Parnell Square, to St Stephen's Green.
The Licensed Vintners Association say all pubs in Dublin City Centre will be open for the full permitted trading hours on the day, and will be selling alcohol.
Meanwhile annual leave for gardai in Dublin has been cancelled on St Patrick's Day, as part of a policing plan.
Assistant Garda Commissioner Angela Willis says: “An Garda Síochána will be implementing a significant policing operation across the Dublin Region on St Patrick’s Day and over the festival weekend to make sure that those attending the various events are able to enjoy themselves and feel safe.
"We expect significant numbers of people to attend the St Patrick’s Day Parade in the city center and also many other events that will be happening across the city.
"We will be working alongside our emergency service partners and others to make the festival safe and enjoyable for all. Our policing plan extends across the transport networks and we expect that there will be significant demands on public transport.
"The festival and parade is family friendly and you can expect high visibility policing; Gardaí are here to help and provide assistance; You can do your part by arriving early and following the instructions of Gardaí and Stewards; An Garda Síochána will be enforcing restrictions on alcohol to keep public realms safe.
"We want everyone to have a great time with family and friends and we will be making safety a priority. The city centre, in particular, will be busy and we remind everyone to remain vigilant when out and about; look after your family, your friends and your property."
Dublin's St. Patrick's Festival weekend celebrations kick-off tomorrow, and will run until Sunday.
The National parade takes to the capital's streets on Friday, with half a million people expected to take in the spectacle.
This year’s National St. Patrick’s Day Parade returns from 12 noon on Friday March 17th, winding its way from Parnell Square to Kevin St Junction.
Lord Mayor Caroline Conroy says: "The return of St. Patrick’s Festival to the streets of Dublin is a wonderful opportunity for our capital city to shine and for those living here and those visiting the city to get out and experience the very best of Irish arts, culture and much more.
"In the spirit of our renowned hospitality, we would also encourage everyone to be welcoming, kind and respectful to one another on St. Patrick’s Day and across the festival."