| Willisau Aukrug | Central European Time | 00:00 |
| Willisau Keswick | United Kingdom Time | 01:00 |
| Willisau Aurora | Eastern Time | 06:00 |
| Willisau Autreppe | Central European Time | 00:00 |
| Willisau Australia Landing | Central Time | 07:00 |
| Willisau Authoor | India Standard Time | -04:30 |
| Willisau Aubergenville | Central European Time | 00:00 |
| Willisau Auburn | Central Time | 07:00 |
| Willisau Auckland | New Zealand Time | -12:00 |
| Willisau Auckland | New Zealand Time | -12:00 |
| Willisau Auckland | New Zealand Time | -12:00 |
| Willisau Auckland | New Zealand Time | -12:00 |
| Willisau Auderghem | Central European Time | 00:00 |
| Willisau Atoka | Central Time | 07:00 |
| Willisau Atlantic Beach | Eastern Time | 06:00 |
| Willisau Attibele | India Standard Time | -04:30 |
| Willisau Attalla | Central Time | 07:00 |
| Willisau Anglesea | Eastern Australia Time | -10:00 |
| Willisau Ange-Gardien | Eastern Time | 06:00 |
| Willisau Ang Sila | Indochina Time | -06:00 |
| Willisau Angadipuram | India Standard Time | -04:30 |
| Willisau Anna Maria | Eastern Time | 06:00 |
| Willisau Ankola | India Standard Time | -04:30 |
| Willisau Anjuna | India Standard Time | -04:30 |
| Willisau Angwin | Pacific Time | 09:00 |
| Willisau Antananarivo | East Africa Time | -02:00 |
| Willisau Anna's Retreat | Atlantic Time | 05:00 |
| Willisau Annandale | Eastern Australia Time | -10:00 |
| Willisau Antibes | Central European Time | 00:00 |
| Willisau Antigonish | Atlantic Time | 05:00 |
| Willisau Antwerp | Central European Time | 00:00 |
| Willisau Anzegem | Central European Time | 00:00 |
| Willisau Anzegem | Central European Time | 00:00 |
| Willisau Arahal | Central European Time | 00:00 |
| Willisau Arad | Israel Time | -01:00 |
| Willisau Arakawa | Japan Time | -08:00 |
| Willisau Aramengo | Central European Time | 00:00 |
| Willisau Arcachon | Central European Time | 00:00 |
| Willisau Arco | Central European Time | 00:00 |
| Willisau Arazane | Western European Time | 00:00 |
| Willisau Appenzell District | Central European Time | 00:00 |
| Willisau Apple Springs | Central Time | 07:00 |
| Willisau Apollo Beach | Eastern Time | 06:00 |
| Willisau Applecross | Western Australia Time | -07:00 |
| Willisau Apt | Central European Time | 00:00 |
| Willisau Aptos | Pacific Time | 09:00 |
| Willisau Arab | Central Time | 07:00 |
| Willisau Arabico | Bolivia Time | 05:00 |
| Willisau Aoulouz | Western European Time | 00:00 |
| Willisau Aougrout | Central European Time | 00:00 |