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Chapter 05Calendar · Practical note

The spring time change list

Quick answer

The clocks go forward at 2 a.m. on the second Sunday in March. That weekend, do four things: book the cooling check-up before contractors get busy for summer, read the date of manufacture on the back of each smoke alarm (ten years past it, the alarm gets replaced), press the test button on every smoke and CO alarm, and look at the HVAC filter. ENERGY STAR suggests the time changes as the reminder for the check-ups.

Source: NIST, daylight saving time rules, checked October 12, 2026; ENERGY STAR maintenance checklist, checked October 15, 2026; USFA, Don't wait, check the date handout, checked October 12, 2026; NFPA, installing and maintaining smoke alarms, checked October 15, 2026; NFPA, carbon monoxide safety, checked October 15, 2026.

Example8 dated jobs a yearCold region, plus 2 monthly checks

The list

  • Book the cooling check-up. ENERGY STAR says contractors get busy once summer comes, so spring is the time to check the cooling system.
  • Read the date of manufacture on the back of each smoke alarm. USFA says smoke alarms are replaced ten years from that date.
  • Press the test button on every smoke alarm and every CO alarm. NFPA says to test both at least once a month, so this is that month's test.
  • Look at the HVAC air filter. ENERGY STAR says to inspect, clean or change it once a month.

Source: ENERGY STAR maintenance checklist, checked October 15, 2026; USFA, Don't wait, check the date handout, checked October 12, 2026; NFPA, installing and maintaining smoke alarms, checked October 15, 2026; NFPA, carbon monoxide safety, checked October 15, 2026.

The spring time change list Four jobs for the weekend the clocks go forward: book the cooling check-up, read the date on the back of each smoke alarm, press the test button on every smoke and CO alarm, look at the HVAC filter. Then write the dates on the year sheet. Clocks go forward: the weekend list 1Book the cooling check-upBefore the summer rush. Renters: ask the landlord when it is booked. 2Read the date on the back of each smoke alarmTen years past that date means it gets replaced. 3Press test on every smoke and CO alarmThe monthly test, done while you are already up there. 4Look at the HVAC filterDirty? Change it, and write the date on the frame. Then write each date on the year sheet.
Fig. 1Four jobs, one weekend. Write each date on the year sheet when you're done.

Why the clocks make a good reminder

ENERGY STAR suggests planning the heating and cooling check-ups around the spring and fall time changes, since they come at about the right point in each season. NIST sets the dates: daylight saving time starts at 2 a.m. on the second Sunday in March and ends at 2 a.m. on the first Sunday in November.

Source: ENERGY STAR maintenance checklist, checked October 15, 2026; NIST, daylight saving time rules, checked October 12, 2026.

In 2027 the spring change falls on March 14, in 2028 on March 12 and in 2029 on March 11.

The second Sunday in March A March 2027 calendar with Sunday the 14th ringed, since the 7th is the first Sunday. A side table lists the spring time change for 2027 (March 14), 2028 (March 12) and 2029 (March 11). March 2027 SunMonTueWedThuFriSat 123456 78910111213 14151617181920 21222324252627 28293031 The 7th is the first Sunday. The 14th is the second: clocks go forward at 2 a.m. Spring time change 202720282029 March 14March 12March 11 Second Sunday in March (NIST) Hawaii and most of Arizona keep their clocks.
Fig. 2The spring change is always the second Sunday in March. Count Sundays, not weeks.

Hawaii and most of Arizona

NIST lists Hawaii, most of Arizona (the Navajo Indian Reservation does change) and the U.S. territories as places that don't observe daylight saving time. The list still works there. Put it on the second weekend of March anyway.

Source: NIST, daylight saving time rules, checked October 12, 2026.

Job 1: book the cooling check-up

This is a phone call, not a repair. Call the company that did the last visit, or pick one, and get a date on the calendar before the first hot week. ENERGY STAR recommends a yearly pre-season check-up by a contractor. What the visit covers is between you and the contractor.

Source: ENERGY STAR maintenance checklist, checked October 15, 2026.

Renting? Ask the landlord or property manager when the cooling check-up is booked, and write their answer on the year sheet.

Job 2: read the date on each smoke alarm

  1. Take the alarm down

    USFA's steps: remove the alarm from the wall or ceiling.

  2. Find the date on the back

    Look for the date of manufacture on the back of the alarm.

  3. Add ten years

    An alarm is replaced ten years from that date. Write the replace-by year on the log.

  4. Put it back if it's younger

    Under ten years old, it goes back on the ceiling or wall.

Hard-wired alarms: wiring safety first

If the alarm has wires behind it, taking it down is wiring work. Switch off and isolate the supply, check it is dead with a tester, follow local wiring rules, and use a licensed electrician where the law requires one. If you'd rather not, write "date unread" on the log and have it read when an electrician is next in the house.

Job 3: test every alarm

Press the test button on each smoke alarm and each CO alarm. NFPA says to test them at least once a month. You're already going room to room for the dates, so the March test takes a couple of extra minutes. If an alarm doesn't sound, write it down and follow the maker's instructions or tell the landlord.

Source: NFPA, installing and maintaining smoke alarms, checked October 15, 2026; NFPA, carbon monoxide safety, checked October 15, 2026.

Job 4: look at the filter

Slide the HVAC filter out and look at it. ENERGY STAR says to inspect, clean or change filters once a month in a central air conditioner, furnace or heat pump. If you put in a new one, write the date on its frame.

Source: ENERGY STAR maintenance checklist, checked October 15, 2026.

Let the tool do the arithmeticHome maintenance calendarThe home maintenance calendar puts these March jobs on a dated year sheet with the rest of your year, from the fall heating call to the first-freeze jobs.Example: 8 dated jobs a year (Cold region, plus 2 monthly checks)Open the tool
One trip down the hall covers the alarm dates and the monthly test.

Write it down

On the year sheet, tick each job and write the date. For the alarms, note each one's replace-by year. For the cooling check-up, write the booked date and the company. The fall list in November picks up from here.

Checklist to print

The weekend the clocks go forward:

  • Book the cooling check-up (renters: ask)
  • Write the booked date and company down
  • Read the date on each smoke alarm
  • Note each alarm's replace-by year
  • Hard-wired: wiring safety first
  • Press test on every smoke alarm
  • Press test on every CO alarm
  • Look at the HVAC filter
  • Date the frame of any new filter
  • Tick the year sheet

Open the printable checklist

Spring time change list

Tips and tricks

  • Tip 01

    Do it Saturday

    The clocks change overnight into Sunday. Doing the list on Saturday leaves Sunday free and gets the cooling call in a day sooner.

  • Tip 02

    Number the alarms first

    A number on each alarm (a small sticker or marker on the base) and the same number on the log makes the date reading quick every year after.

  • Tip 03

    Ask about the CO alarm's life

    NFPA says CO alarms are replaced according to the manufacturer's instructions, not on the ten-year smoke alarm rule. Look at the back or the manual for the maker's date.

    Source: NFPA, carbon monoxide safety, checked October 15, 2026.

  • Tip 04

    Buy filters while you're at it

    If the filter shelf is empty after the filter check, add filters to the shopping list that day.

What we would do

One hour on the Saturday before the clocks change

Book the cooling check-up first, since that's the one with a waiting list. Then walk the house once: take each smoke alarm down, read the date, press test, put it back. Finish at the filter. Write everything on the year sheet before you put the pen down.

Questions

When do the clocks go forward?

At 2 a.m. local time on the second Sunday in March, per NIST. In 2027 that's March 14.

Source: NIST, daylight saving time rules, checked October 12, 2026.

Should I change smoke alarm batteries when the clocks change?

NFPA says alarms with replaceable batteries get a new battery at least once a year, and sealed 10-year alarms are replaced when they chirp for low battery. Our calendar puts the yearly battery job on the fall change. In spring, read the dates and test.

Source: NFPA, installing and maintaining smoke alarms, checked October 15, 2026.

When should I get my AC serviced?

ENERGY STAR says spring, because contractors get busy once summer comes, and suggests the spring time change as the reminder.

Source: ENERGY STAR maintenance checklist, checked October 15, 2026.

How do I know how old my smoke alarm is?

The date of manufacture is on the back. USFA says to replace the alarm ten years from that date.

Source: USFA, Don't wait, check the date handout, checked October 12, 2026.

What if my state doesn't change the clocks?

Hawaii and most of Arizona don't observe daylight saving time, per NIST. Do the list on the second weekend of March anyway.

Source: NIST, daylight saving time rules, checked October 12, 2026.

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