| Guyancourt Lovington | Mountain Time | 08:00 |
| Guyancourt Henrico | Eastern Time | 06:00 |
| Guyancourt North Syracuse | Eastern Time | 06:00 |
| Guyancourt Brinchang | Malaysia Time | -06:00 |
| Guyancourt Tabio | Colombia Time | 07:00 |
| Guyancourt Saint-Hubert | Central European Time | 00:00 |
| Guyancourt Sidmouth | United Kingdom Time | 01:00 |
| Guyancourt Brisbane City | Eastern Australia Time | -08:00 |
| Guyancourt Lower Heyford | United Kingdom Time | 01:00 |
| Guyancourt Funes | Argentina Time | 05:00 |
| Guyancourt North Palm Beach | Eastern Time | 06:00 |
| Guyancourt Brisighella | Central European Time | 00:00 |
| Guyancourt Üsküdar | Turkey Time | -01:00 |
| Guyancourt Saint Leonards | Eastern Australia Time | -08:00 |
| Guyancourt Scarborough | Eastern Time | 06:00 |
| Guyancourt Brighton-Le-Sands | Eastern Australia Time | -08:00 |
| Guyancourt Lourinhã | Western European Time | 01:00 |
| Guyancourt Funes | Central European Time | 00:00 |
| Guyancourt North Parramatta | Eastern Australia Time | -08:00 |
| Guyancourt Brighton | Eastern Australia Time | -08:00 |
| Guyancourt Urumqi | China Time | -06:00 |
| Guyancourt Saint Leonards | United Kingdom Time | 01:00 |
| Guyancourt Scarness | Eastern Australia Time | -08:00 |
| Guyancourt Brighton | Eastern Time | 06:00 |
| Guyancourt Lovedale | Eastern Australia Time | -08:00 |
| Guyancourt Fulbourn | United Kingdom Time | 01:00 |
| Guyancourt North Perth | Western Australia Time | -06:00 |
| Guyancourt Briviesca | Central European Time | 00:00 |
| Guyancourt Ursel | Central European Time | 00:00 |
| Guyancourt Saint-Leonard | Eastern Time | 06:00 |
| Guyancourt Scarperia e San Piero | Central European Time | 00:00 |
| Guyancourt Broadbeach | Eastern Australia Time | -08:00 |
| Guyancourt Lourenzá | Central European Time | 00:00 |
| Guyancourt Fulchur | India Standard Time | -03:30 |
| Guyancourt Orthez | Central European Time | 00:00 |
| Guyancourt Broadbridge Heath | United Kingdom Time | 01:00 |
| Guyancourt Urmar Tanda | India Standard Time | -03:30 |
| Guyancourt Saint Johns | Eastern Time | 06:00 |
| Guyancourt Schaerbeek | Central European Time | 00:00 |
| Guyancourt Broadmeadows | Eastern Australia Time | -08:00 |
| Guyancourt Lost Hills | Pacific Time | 09:00 |
| Guyancourt Fuhlsbüttel | Central European Time | 00:00 |
| Guyancourt Orvieto Scalo | Central European Time | 00:00 |
| Guyancourt Carhaix-Plouguer | Central European Time | 00:00 |
| Guyancourt Vouni | Eastern European Time | -01:00 |
| Guyancourt Saint John | Central Time | 07:00 |
| Guyancourt Sidon District | Eastern European Time | -01:00 |
| Guyancourt Cardona | Central European Time | 00:00 |
| Guyancourt Lotzwil | Central European Time | 00:00 |
| Guyancourt Fujairah | Gulf Standard Time | -02:00 |