As summer comes to an end and the nights become longer, people across the nation are preparing to set reminders to put their clocks back an hour on 29 October to reflect the change in season.

Despite this routine occurring twice every year, many people are caught out by the extra hour lost or gained. But for people with dementia, the time change may cause more than just a surprise.

The UK's leading dementia charity, Alzheimer's Society, has advised that people with dementia can find themselves disorientated by the clocks moving back.

As winter mornings become darker, people with dementia may find it difficult to differentiate between 6am and 6pm disrupting their circadian biological clock - making it hard for them and those who care for them to get enough sleep.

Some people with dementia might also experience something called 'sundowning' when the days get shorter. Sundowning refers to a change in behaviour in the later afternoon or towards the end of the day. During this time, the person may become intensely distressed or confused.

Dr Tim Beanland, Head of Knowledge at Alzheimer's Society, said:

"For the majority of people, the annual daylight-saving clock change is simply met with a light-hearted shrug and a set reminder to identify all the clocks you own to wind back an hour – don't forget the clock on the oven! While it can be a minor nuisance for the majority of people, for people living with dementia it can trigger anxiety, confusion and irritability."

Here are three top tips from Alzheimer's Society to help people with dementia overcome challenges faced by the clock change:

1. Having a routine during the day and at bedtime can help regulate a person's disrupted body clock. Doing regular activities at the same time each day – for example going for a walk after breakfast, can help a person with dementia make sense of the time.
2. Going outside in the morning, can help set a person's body clock too, making them feel sleepier during the evening. If the person is unable to go outside, the same effect can be created by switching on a lamp or lightbox.
3. Alzheimer's Society's online shop sells various 'Day and Night' clocks which have all the features of a traditional clock, but also include simple day and night visual symbols to help people with dementia distinguish the time of day. The clock can be purchased here: Day and Night Clock – Alzheimer's Society Shop (alzheimers.org.uk)

"Too many people face dementia alone. We want everyone affected by dementia to know that whoever you are, whatever you're going through, you can turn to Alzheimer's Society for practical advice, emotional support, and guidance for the best next step," added Dr Beanland.

There are 900,000 people with dementia in the UK. This is projected to rise to 1.6 million people by 2040.

If you're affected by dementia, call Alzheimer's Society's support line on: 0333 150 3456 or visit alzheimers.org.uk.