In Denmark a lot of families eat at either 6 p.m. or 7, depending on when they get home from work and on the age of the children.
Office staff rarely can leave work before 5 p.m. or 5.30 at the earliest, shop staff work shifts so there is no general rule for when they will get home from work, and the same applies to hospital staff and care home staff.
A lot of people have an hour or an hour and a half's travelling time between their place of work and their home.
It is thus always wise to check if you are invited to dinner when the family actually eats.
As a general rule, you can expect families with young children to eat as soon as possible after coming home from work in order to get the children bathed and to bed at a reasonable hour.
Families with school-children may not actually eat together on week days, as one or more child or adult may be going to sports, scouts, visiting friends etc. after school or work.
If only one adult in the family works full-time the other may do all the shopping and cooking - if they work shifts you may well find that the person who gets off work earliest shops and collects children from day-care or school, ferries children to and from after-school activities and the other does the cooking.
Again there are no longer general rules or set times for meals, although Danish restaurants usually do not serve food after 9 or 10 p.m. so obviously people are used to eating their evening meal somewhere between 6 p.m. and 9.
I am 70, and not since my childhood has there been set times for meals in cities and a different set of times in country areas, where the farming community continued eating their main meal at midday or one o' clock, a practice that is still maintained by hospitals and care homes due to staffing, as evening staff are paid at a higher rate than daytime staff.
In Spain where in my experience the evening meal is often eaten around nine in the evening, people tend to eat a light snack on their way home from work.