Thereafter, the Guernsey flag was used in the Grosse Rocque ceremony, replacing the Union Jack, which had traditionally been raised on Grosse Rocque every August bank holiday. The flag would then fly on the rock continuously for a year before being replaced with a new one. The flag of Guernsey is flown from all of the States of Guernsey buildings except on designated flag-flying days, when the Union Jack is used instead. These days mostly relate to birthdays and anniversaries of senior members of the Royal Family as well as Commonwealth Day and Remembrance Sunday. The flag is also flown on the anniversary of the Battle of Hastings on all public buildings.
The flag provided inspiration for the flag of Alderney in 1993. It has also inspired other symbols. In 2011, the Guernsey Ambulance and Rescue Service adopted a new logo comprising the Cross of St George and gold Norman cross, but defaced by the Maltese Cross of the Venerable Order of Saint John based on the Guernsey flag. In November 2012 the Bailiwick of Guernsey‘s St John Ambulance was elevated to a Commandery within the Order dependent on the Priory of England and the Islands in a church service which included granting a new flag from the British College of Arms including elements of the flag of Guernsey.
The flag is not universally supported. Some Guernsey sports fans complain that the flag lacks Guernsey’s sporting color of green or the crest of Guernsey. In the 2000s, a green and white tricolor with the coat of arms of Guernsey in the center was created by Guernsey sports fans to be used as Guernsey’s unofficial sporting flag.