Parents on higher salaries are more likely to have flexible work arrangements, a new study shows.
Research by charity Working Families also found that most working families did extra unpaid hours every week, saying it interfered with their ability to put their children to bed.
The charity dubbed today Go Home On Time Day as part of its campaign to promote a decent work/life balance.
Sarah Jackson, chief executive of Working Families, said: "Families need time as well as money to thrive, but one shouldn't depend on the other.
"We know flexible working makes business sense across the salary spectrum, so why should only the people who earn the most be able to reap the rewards?
"We want jobs at all levels to be advertised as flexible. This should be the norm, rather than the exception.
"Everyone has the right to request flexible work patterns so we hope more employees - and employers - will use today's status as Go Home On Time Day as an opportunity to explore the benefits."
The survey of 1,000 working parents found that those on more than £70,000 a year were more likely to work flexibly.