Middle Tennessee gets its share of storms, and a power cut can quietly wreck a lighting schedule.
Mechanical dial timers stop when the power stops and start again when it returns, behind by the length of the outage. Three hours without power means lights running three hours late until someone resets the dial.
Digital timers often hold the time and program on a small backup battery or capacitor for a while. Once that runs down, many reset to 12:00 and some lose their programs. The manual says which kind you have.
Astronomic timers behave like digital ones and may also need the date entered again.
Photocells have nothing to forget.
Smart plugs, bulbs and app-run systems usually keep their schedules, either on the device or in an online account. When power returns they need the home network to get the correct time. If the router is slow to come back, the lights may skip a night or run from a stored schedule until it does.
Look at every timer with a display. A blinking 12:00 means it reset.
Set each mechanical dial to the current time.
Open each lighting app and confirm every device shows as online.
If a timer plugged into an outdoor outlet stays dark, check whether that outlet's GFCI has tripped, and press its reset button.
That evening, check from the street that the right lights came on at the right time.
Ready.gov advises turning off or unplugging appliances and electronics during an outage, because power can come back with surges or spikes that cause damage. Plug-in timers and lighting controllers count as electronics. Once power has been steady for a while, plug them back in and run the check above.
Outage maps and reporting come from the utility, not from your lighting. Nashville Electric Service runs an outage map for its customers. Middle Tennessee Electric, which serves much of the surrounding area, runs its own outage center.