UTC+0
Europe:
🇬🇧 United Kingdom (winter only — BST in summer)
🇵🇹 Portugal (winter only — WEST in summer)
🇮🇪 Ireland (winter only — IST in summer)
🇮🇸 Iceland (year-round, no DST)
🇫🇴 Faroe Islands (winter only)
Africa:
🇬🇭 Ghana (year-round)
🇸🇳 Senegal (year-round)
🇨🇮 Ivory Coast (year-round)
🇧🇫 Burkina Faso (year-round)
🇬🇲 Gambia (year-round)
🇬🇳 Guinea (year-round)
🇬🇼 Guinea-Bissau (year-round)
🇲🇱 Mali (year-round)
🇲🇷 Mauritania (year-round)
🇸🇱 Sierra Leone (year-round)
🇹🇬 Togo (year-round)
🇸🇹 São Tomé and Príncipe (year-round)
🇱🇷 Liberia (year-round)
Atlantic:
🇸🇭 Saint Helena (year-round)
Greenwich Mean Time (GMT) is the time at the Prime Meridian — longitude 0° — which passes through the Royal Observatory in Greenwich, London. It serves as the baseline for all other time zones worldwide and is equivalent to UTC+0.
GMT is observed year-round in countries that do not use Daylight Saving Time. The United Kingdom uses GMT in winter, switching to British Summer Time (BST, UTC+1) between late March and late October.