Most people stop when the sun is reliably up before they are, which for a 7 am start means late February in London, the first days of March in Manchester and Cardiff, and the second week of March in Belfast and Inverness. There is no rule that says you must stop, and no harm in tapering rather than quitting, but a bright lamp on a bright spring morning is doing a job the sky has already done. Here is how to judge the date for yourself.
What is the lamp for, and when does the sky take over?
A morning lamp stands in for the bright daylight that sets the body clock at the start of the day. Its job ends when that daylight is back at the time you wake. The relevant question is therefore not "is it spring?" but "is it light when I get up?", and the answer depends on where you live and what time your alarm goes off.
| City | Sunrise before 7 am from | Sunrise before 6.30 am from (after clocks go forward) | Day length on 1 March / 1 April / 1 May |
|---|---|---|---|
| London | 23 February | 5 April | 10.9 h / 12.9 h / 14.8 h |
| Manchester | 1 March | 7 April | 10.8 h / 13.0 h / 15.0 h |
| Glasgow | 5 March | 9 April | 10.7 h / 13.1 h / 15.3 h |
| Belfast | 7 March | 12 April | 10.8 h / 13.0 h / 15.2 h |
| Inverness | 6 March | 8 April | 10.6 h / 13.2 h / 15.6 h |
Two things complicate the calendar. The clocks go forward on 28 March 2027, which sets the sunrise back by an hour overnight: London goes from a 05:48 sunrise on 27 March to 06:45 on the 28th. And a grey morning is much dimmer than a clear one, though still far brighter than a lit room, as how bright is a cloudy day in the UK? shows. The dates above are for a sunrise that has happened; if you wake at 6 am, add two or three weeks to each.
Should you stop suddenly or taper?
Either is fine. The research on seasonal affective disorder generally treated the lamp as a winter intervention that ends when the days lengthen, which is an argument for judging the date by your own mornings rather than by the calendar: a dark week in February is still winter. A practical approach is to shorten sessions as the mornings brighten, then swap the lamp for the walk, the garden or the open curtain that is now available. Consistency in wake time matters more than which light source you use. Should you use a SAD lamp every day, and what about summer? covers the year-round question.
Who might keep going longer?
People whose mornings stay dark for reasons other than the season: shift workers, very early starters, anyone in a north-facing flat with no morning window, and people who are using morning light to keep a late body clock in check. For them the lamp is not seasonal at all. Light therapy for shift workers and night owls: can morning light shift a late body clock? cover those cases, and dark flats and north-facing rooms the housing one.
Is there a reason to stop earlier?
The main one is side effects that have crept in, such as headaches, eye strain or feeling wired, which usually mean the dose is too high for the season; move the lamp further away or shorten the session before giving up entirely. Light therapy lamp side effects explains the adjustments. The NHS advice to speak to a GP first if you have an eye condition, a condition affected by bright light or take medicines that increase light sensitivity applies whatever the month.
Frequently asked questions
Can I use the lamp all year?
You can, though most people find it redundant from April to September. If you like the routine, a shorter session or a lower setting keeps the habit without over-egging it.
What if I stop and feel worse?
Start again; nothing is lost. If low mood persists into the lighter months, or does not follow the seasons at all, that is a reason to see your GP rather than to rely on a lamp. Winter blues vs SAD explains the difference.
When should I start again in the autumn?
Around the time the sun rises after your alarm again, which for a 7 am start is the second half of September in Scotland and Northern Ireland and the start of October in London, with the clocks going back on 31 October 2027. When to start using a SAD lamp in the UK has the full calendar.
Should I store the lamp or leave it out?
Store it clean and dry; how long does a light therapy lamp last? covers cleaning and care. Leaving it on the table where it lives makes the autumn restart easier.
Where does this leave you?
Stop when the sky is doing the job: for most of the UK that is somewhere between the last week of February and the second week of March, later if you are up before 6.30. Taper if you like, keep the wake time steady, and let daylight take over. The lamp will be needed again in October. Until then, the UK daylight hours by month guide shows how much light you are gaining each week.
About DAYARC
DAYARC is a new UK circadian rhythm startup. We make two bright-light lamps for the morning: DAYARC Rise (£199), a full-size lamp rated at 10,000 lux at approximately 30–36 cm, with four brightness settings, a 15 to 60-minute timer and adjustable height and angle; and DAYARC Mini (£49.99), a compact lamp rated at 10,000 lux at approximately 25 cm, with a folding stand that doubles as its cover. Both use UV-free LEDs and run from the mains. We publish plain specifications with the measuring distance, we do not make medical claims, and we write the DAYARC Journal to help people build a simple morning light routine around their own daily rhythm. You can read more about how we think on our approach page or compare the two lamps.
This article is general information, not medical advice. Check with a GP or qualified healthcare professional before using bright light if you have an eye condition, a condition affected by bright light such as bipolar disorder, or take medicines that increase your sensitivity to light. If you have persistent low mood or think you may have depression, speak to your GP. If you need urgent help, contact NHS 111, or call 999 in an emergency.