Area code 636
Area code 636 serves St. Charles and nearby parts of Missouri, including O'Fallon, Wentzville and Chesterfield. It is on Central Time, which observes daylight saving time.
Area code 636 at a glance
| State | Missouri (MO) |
| Main city | St. Charles |
| Time zone | Central Time |
| UTC offset | UTC−6 in winter, UTC−5 in summer |
| Daylight saving time | Yes |
Cities in 636
- St. Charles
- O'Fallon
- Wentzville
- Chesterfield
An area code shows where a number was first assigned. Mobile numbers keep their area code when people move, so the person you’re calling may be somewhere else.
When you can call a 636 number
Federal telemarketing rules under the TCPA allow sales calls between 8 AM and 9 PM in the called person’s local time. Here is that window for a 636 number, shown in your own time zone.
General information, not legal advice. Some states add rules for Sundays, holidays or the number of calls. See our calling hours guide.
| If you’re on | You can call 636 between |
|---|---|
| Eastern | 9:00 AM to 10:00 PM |
| Central | 8:00 AM to 9:00 PM |
| Mountain | 7:00 AM to 8:00 PM |
| Arizona | 6:00 AM to 7:00 PM |
| Pacific | 6:00 AM to 7:00 PM |
See the time in 636 without leaving your CRM
Parse is a free Chrome extension that shows the local time and weather beside every phone number on the page.
Other area codes in Missouri
Questions about 636
What time zone is area code 636?
Area code 636 is on Central Time. It observes daylight saving time.
Where is area code 636?
Area code 636 is in Missouri. Its main city is St. Charles, and it also covers O'Fallon, Wentzville and Chesterfield.
What are the legal hours to call a 636 number?
Under the federal TCPA, sales calls are allowed from 8 AM to 9 PM in the called person’s local time. Personal and informational calls are not limited by these hours.