Sleep. Whether your child gets enough or not it is a topic of conversation most often heard among parents, especially those of babies.
And just when you think you have got it sussed something else changes.
Tonight the clocks go back one hour but Baby Sleep Consultant Emma Purdue says it doesn't have to mean the end of the world.
Emma is a scientist and a teacher - she has a Bachelor of Science and Diploma in Education from the University of Auckland - and also a mother of three, so has been practicing her sleep training methods since her eldest was born almost six years ago.
She has been in business since November and in that time has helped more than 200 babies and toddlers improve their sleep patterns. Before setting up her consultancy Emma helped 100 babies, all after trialling methods with her own children.
"When I had my first I had no idea about sleep, I just thought they would go to sleep. I started reading everything I could and it turned out it was very scientific and then it turned out I was good at getting other babies to sleep.
"I would do it by email, visit parents in the middle of the night and get their babies to sleep for them, then people said I should start a business. It's really satisfying."
She says she spent more time educating herself before opening Baby Sleep Consultant for business in November. Opening her emails each day is a mix of joy from parents who have experienced eight hours sleep to those desperate for help.
"I think it helps I've been there. I know just how exhausted and frustrated they can be."
With daylight saving coming to an end tonight Emma has already adjusted her own children's sleep patterns in readiness, but she says parents who haven't tackled it pro-actively can still make up for it by starting on Monday.
If your child is waking at 6am instead of 7am try to push that until 6.15am, move nap and feed times 15 minutes later than normal and have bedtime at 6.15pm instead of 6pm. On Tuesday do the same as for Monday.
On Wednesday push the morning wake up time to 6.30am, move morning naps and feed times to 30 minutes later than usual, so an extra 15 minutes to the previous days. Have bed time at 6.30pm. Repeat on Thursday.
On Friday push the morning wake up to 6.45am and move the nap and feed times back by a further 15 minutes. Have bed time at 6.45pm. Repeat on Saturday.
This means that by Sunday you should be experiencing a 7am wake up and all nap and feed times have been pushed forward by an hour.
"It's important to move feed times as circadian rhythms react to food and light. The other approach is to see how they sleep after the clocks change and take it from there."
Emma says any child aged 6 months or older is affected by clock changes as when they are younger their sleep cycles can be more easily manipulated. Once they hit 6 months their sleep is more controlled by light.
"So use distraction and games to push feeds forward as well as naps, this will help regulate things quickly - even if it cools down where you live, try to get outside for some sunlight first thing in the morning and late in the afternoon."
Emma's website www.babysleepconsultant.co.nz is full of advice and tips on sleep and she is quick to admit that there is no one method to getting a baby to sleep well.
"I have three children, two were thumb suckers, the other sucks a cuddly. I'm not a one-size fits all person. I give three options and let the parents choose the one they're most comfortable with."