Sarah Jackson, chief executive of Working Families, said: "We organise Go Home on Time Day to highlight the impact that long hours at work can have on family life, but more importantly to encourage people to make a conscious decision to have at least one day when they will leave work on time during the working week - not just once, but all year round."
A spokesman for Bisto, which is sponsoring the day, said: "It's encouraging to see that families are still sitting down for dinner together, but it's important that everyone gets the opportunity to share this quality time with each other, especially as our working lives become more stressful and working hours get longer."
Firms were urged to encourage staff to avoid planning meetings or activities that will start within an hour of their usual finishing time, and to consider banning all business travel for the day.