Why dont you use CET (Central European Time) instead of GMT which is used by only one country ?
CET countries: Albania, Andorra, Austria, Belgium, Bosnia & Herzegovina, Croatia, Czech, Denmark, France, Germany, Gibraltar, Vatican City, Hungary, Italy, Liechtenstein, Luxembourg, Macedonia, Malta, Monaco, Netherlands, Norway, Poland, San Marino, Serbia-Montenegro, Slovakia, Slovenia, Spain, Sweden, Switzerland
GMT: UK