| Willisau Ifran | Western European Time | 00:00 |
| Willisau Idlib | Eastern European Time | -01:00 |
| Willisau Idukki Township | India Standard Time | -04:30 |
| Willisau Idyllwild-Pine Cove | Pacific Time | 09:00 |
| Willisau Ichikawa | Japan Time | -08:00 |
| Willisau Idar | India Standard Time | -04:30 |
| Willisau Idalia | Eastern Australia Time | -09:00 |
| Willisau Illueca | Central European Time | 00:00 |
| Willisau Ilavala Hobli | India Standard Time | -04:30 |
| Willisau Ileret | East Africa Time | -02:00 |
| Willisau Iligan City | Philippine Time | -07:00 |
| Willisau Ilford | United Kingdom Time | 01:00 |
| Willisau Ilfracombe | United Kingdom Time | 01:00 |
| Willisau Ikšķile | Eastern European Time | -01:00 |
| Willisau Humboldt | Central Time | 07:00 |
| Willisau Hunter River | Atlantic Time | 05:00 |
| Willisau Hulshout | Central European Time | 00:00 |
| Willisau Hultsfred | Central European Time | 00:00 |
| Willisau Hulu Langat | Malaysia Time | -07:00 |
| Willisau Huixquilucan de Degollado | Central Time | 07:00 |
| Willisau Hudson | Eastern Time | 06:00 |
| Willisau Hudson Oaks | Central Time | 07:00 |
| Willisau Hubali-Dharwad | India Standard Time | -04:30 |
| Willisau Huez | Central European Time | 00:00 |
| Willisau Hudsonville | Eastern Time | 06:00 |
| Willisau Huehuetoca | Central Time | 07:00 |
| Willisau Hyde Park | Eastern Australia Time | -09:00 |
| Willisau Hyderabad | India Standard Time | -04:30 |
| Willisau Hyderabad | India Standard Time | -04:30 |
| Willisau Hyderabad | India Standard Time | -04:30 |
| Willisau Hyderabad | India Standard Time | -04:30 |
| Willisau Huntingdale | Western Australia Time | -07:00 |
| Willisau Huttons Ambo | United Kingdom Time | 01:00 |
| Willisau Huskisson | Eastern Australia Time | -10:00 |
| Willisau Húsavík | Greenwich Mean Time | 01:00 |
| Willisau Husborne Crawley | United Kingdom Time | 01:00 |
| Willisau Hurstville | Eastern Australia Time | -10:00 |
| Willisau Hurricane | Mountain Time | 08:00 |