Denver Time| City | Area Code | Dialing Code |
| Arvada | 720 | +1 720 |
| Aspen | 970 | +1 970 |
| Aurora | 630 | +1 630 |
| Boulder | 303 | +1 303 |
| Brighton | 303 | +1 303 |
| Broomfield | 720 | +1 720 |
| Canon City | 719 | +1 719 |
| Castle Rock | 303 | +1 303 |
| Colorado Springs | 719 | +1 719 |
| Commerce City | 303 | +1 303 |
| Denver | 303 | +1 303 |
| Durango | 970 | +1 970 |
| Englewood | 720 | +1 720 |
| Erie | 814 | +1 814 |
| Fort Collins | 970 | +1 970 |
| Golden | 303 | +1 303 |
| Grand Junction | 970 | +1 970 |
| Greeley | 970 | +1 970 |
| Lafayette | 337 | +1 337 |
| Lakewood | 303 | +1 303 |
| Littleton | 720 | +1 720 |
| Longmont | 720 | +1 720 |
| Louisville | 502 | +1 502 |
| Loveland | 970 | +1 970 |
| Montrose | 970 | +1 970 |
| Parker | 303 | +1 303 |
| Pueblo | 719 | +1 719 |
| Westminster | 720 | +1 720 |
| Wheat Ridge | 303 | +1 303 |
| Windsor | 519 | +1 519 |