| Willemstad Obertrubach | Central European Time | -06:00 |
| Willemstad Oberwesel | Central European Time | -06:00 |
| Willemstad Oberkorn | Central European Time | -06:00 |
| Willemstad Oberlin | Eastern Time | 00:00 |
| Willemstad Obernberg am Brenner | Central European Time | -06:00 |
| Willemstad Oaxaca | Central Time | 01:00 |
| Willemstad Oamaru | New Zealand Time | -16:00 |
| Willemstad Oakdale | United Kingdom Time | -05:00 |
| Willemstad Oakdale | Pacific Time | 03:00 |
| Willemstad Oakham | United Kingdom Time | -05:00 |
| Willemstad Oakhurst | Pacific Time | 03:00 |
| Willemstad Oaklands Park | Central Australia Time | -13:30 |
| Willemstad Nyaungshwe | Myanmar Time | -10:30 |
| Willemstad Oak Bluffs | Eastern Time | 00:00 |
| Willemstad Oak Brook | Central Time | 01:00 |
| Willemstad Oak Park Heights | Central Time | 01:00 |
| Willemstad Oak Hill | Eastern Time | 00:00 |
| Willemstad Oak Island | Eastern Time | 00:00 |
| Willemstad Neuerburg | Central European Time | -06:00 |
| Willemstad Neuhausen am Rheinfall | Central European Time | -06:00 |
| Willemstad Neuenbürg | Central European Time | -06:00 |
| Willemstad Neuenburg am Rhein | Central European Time | -06:00 |
| Willemstad Neutral Bay | Eastern Australia Time | -14:00 |
| Willemstad Neutraubling | Central European Time | -06:00 |
| Willemstad Neuried | Central European Time | -06:00 |
| Willemstad Neuötting | Central European Time | -06:00 |
| Willemstad Neuperlach | Central European Time | -06:00 |
| Willemstad Neupré | Central European Time | -06:00 |
| Willemstad Nyaung-U | Myanmar Time | -10:30 |
| Willemstad New Cumberland | Eastern Time | 00:00 |
| Willemstad New Castle | Atlantic Time | 00:00 |
| Willemstad New Carrollton | Eastern Time | 00:00 |
| Willemstad New Buffalo | Eastern Time | 00:00 |
| Willemstad Nevada City | Pacific Time | 03:00 |
| Willemstad New Abbey | United Kingdom Time | -05:00 |
| Willemstad New Bagan | Myanmar Time | -10:30 |
| Willemstad New Baltimore | Eastern Time | 00:00 |
| Willemstad New Barnet | United Kingdom Time | -05:00 |