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The date on your faxes is wrong because the machine's clock reset, usually after a power outage or because its small backup battery died. Fax machines keep time with an internal clock, not the phone line, so nothing corrects it automatically. The fix is to reset the date and time in the machine's setup menu.
| Cause | What happens | How to tell |
|---|---|---|
| Power outage | The clock restarts from the factory default date | Date shows something like Jan 1 2000 or the machine's release year |
| Dead backup battery | Settings fade even without an outage; the clock loses time or resets on unplugging | Date resets every time the machine loses power, even briefly |
| Daylight saving change | The machine does not spring forward or fall back on its own | Time is off by exactly one hour, date is right |
| Wrong format entered | Someone set the date in the wrong order (day vs month) | The header shows an impossible or odd-looking date |
The backup battery detail catches people off guard. Many fax machines keep the clock and settings alive on a small internal battery or capacitor when unplugged. After years of service that battery dies, and from then on every power flicker wipes the clock. If your machine loses its date every time someone unplugs it to move it, that is the battery, not the outage. On most machines the battery is not user-replaceable, which is worth knowing before you pay for a service call.
The setting lives in the machine's initial setup menu, usually under "Date and Time," "Clock Set," or "Initial Setup." The steps are nearly the same across brands:
After setting it, send a test fax to yourself or a colleague and check the header line at the top of the page. That header is where the wrong date shows up, so it is also where you confirm the fix.
Because the date on a fax is often treated as evidence of when something was sent. The header line and the confirmation page both carry timestamps, and people file them as proof: the insurance claim was faxed before the deadline, the notice went out on the required date. If the machine's clock says last March, your proof says last March, and explaining "the clock was wrong" after the fact is awkward at best.
There is a related trap worth knowing about: a wrong date can look like backdating. If a fax header shows a date earlier than the real send date, anyone reviewing it later may read intent into what was just a dead battery. Keeping the clock accurate protects you from that conversation entirely. Check the date after every power outage, and glance at the header line now and then as a habit.
Right, most fax machines have no idea daylight saving exists. They are not connected to the internet and do not receive time signals over the phone line, so the clock just keeps ticking through the change. Twice a year, the time in your fax headers will be off by an hour until someone fixes it by hand. Offices that fax time-sensitive documents often add "check the fax clock" to their spring and fall routines.
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