| Grinnell Wiltz | Central European Time | -07:00 |
| Grinnell Winchcombe | United Kingdom Time | -06:00 |
| Grinnell Windcrest | Central Time | 00:00 |
| Grinnell Windeck | Central European Time | -07:00 |
| Grinnell Winder | Eastern Time | -01:00 |
| Grinnell Windham | Eastern Time | -01:00 |
| Grinnell Winchester | Eastern Time | -01:00 |
| Grinnell Yunquera de Henares | Central European Time | -07:00 |
| Grinnell Yuo | West Africa Time | -06:00 |
| Grinnell Williamstown | Eastern Time | -01:00 |
| Grinnell Williamsville | Eastern Time | -01:00 |
| Grinnell Williamstown | Eastern Australia Time | -15:00 |
| Grinnell Williams | Mountain Time | 02:00 |
| Grinnell Williamsburg | Eastern Time | -01:00 |
| Grinnell Willoughby | Eastern Australia Time | -15:00 |
| Grinnell Willisau | Central European Time | -07:00 |
| Grinnell Williston Park | Eastern Time | -01:00 |
| Grinnell Willits | Pacific Time | 02:00 |
| Grinnell Willaston | United Kingdom Time | -06:00 |
| Grinnell Wilkau-Haßlau | Central European Time | -07:00 |
| Grinnell Wilkesboro | Eastern Time | -01:00 |
| Grinnell Wildwood | Eastern Time | -01:00 |
| Grinnell Wiesbaden | Central European Time | -07:00 |
| Grinnell Wieselburg | Central European Time | -07:00 |
| Grinnell Wilbraham | Eastern Time | -01:00 |
| Grinnell Wildau | Central European Time | -07:00 |
| Grinnell Wilder | Eastern Time | -01:00 |
| Grinnell Wilderswil | Central European Time | -07:00 |
| Grinnell Wickham | United Kingdom Time | -06:00 |
| Grinnell Wickham Bishops | United Kingdom Time | -06:00 |
| Grinnell Wicklow | Ireland Time | -06:00 |
| Grinnell Widnau | Central European Time | -07:00 |
| Grinnell Valkenburg | Central European Time | -07:00 |
| Grinnell Whitney | Central Time | 00:00 |
| Grinnell Zahara de los Atunes | Central European Time | -07:00 |
| Grinnell Zachary | Central Time | 00:00 |
| Grinnell Yvoir | Central European Time | -07:00 |
| Grinnell Yzeure | Central European Time | -07:00 |