A new study has found that on average people start checking their emails at 7.42am and don't stop until almost 12 hours later, at 7.19pm.
The survey of 1000 European and United States workers and bosses by Seattle technology company Mozy said the advent of smartphones and cloud computing meant workers were always in touch with the office.
And it found three-quarters of bosses don't mind employees being half an hour late because they are confident they will have been working elsewhere.
"The days of working 9 to 5 are long behind us," said the report.
Construction company Gemco director, Darren Diack, says he checks his emails constantly "to spread out the load".
"Since I've had the iPad emails are when you are awake," he said.
"I take my daughter to swimming twice a week so I check them at 5am at the pool.
In the evening I check them up to 10pm, but only because of the iPad - it is so convenient."
He said emails were making fax machines obsolete.
"With tendering, the fax was always very important, but now the fax gets used only 10 per cent of the time it used to."
Broadcaster Paul Holmes said he checked his emails constantly. "I check them on the go, wherever I am - I am up to date whether I am in Hawke's Bay or Auckland," he said.
One of Hawke's Bay's most successful businessmen, Ray McKimm of Big Save Furniture and Ahuriri Business Park, said all businesses rely on email but he personally has given up on it.
"In my case it would be nothing to take 200 emails in a day," he said.
"I recognise a lot of activity - reply and action - is quicker than in the past, but it is taking the human element out.
"It is a very direct system but often when you are dealing with the human element it's not what is in the email that ends up being important.
"Over the years I have found with staff they will sometimes put their concerns in an email, but when you talk with them for five minutes you get the real concern.
"I do realise with emails you are receiving instant-time information and people are very reliant on it, but sometimes the human element is important."
A report published this year by workplace provider Regus found New Zealanders' work-life balance to be better than the global average.
A Department of Labour spokeswoman said there was no legal limit to the number of hours a day or days in a row an employee could work. It was a matter for agreement between employer and employee.