But as the ranks of grandparents swell worldwide, and they play a bigger role in their grandchildren’s lives and future happiness than past generations, there is no better time to celebrate the grandparents and surrogate grandparents in your life.

Society, both in Australia and worldwide, is changing.

An unprecedented 18 per cent of the world’s population are now grandparents, making up a bigger chunk of the population than ever before.

Three quarters of adults will one day become grandparents, and some of us will be grandparents for a third of our lives.

Because people are living longer, we are also experiencing a great-grandparent boom.

By 2030, it is expected that most 8-year-olds will have at least one living great-grandparent.

It’s not only the number of grandparents and great-grandparents that has changed.

Just a generation ago, most Australian grandparents were only expected to provide occasional babysitting duties, hand out treats on special occasions and offer advice.

But the role of modern grandparents has been rewritten, with today’s grandparents playing a much bigger role in the lives of their families.

As hands-on providers of childcare, grandparents have never been more visible or indispensable to working parents.

A recent survey found that 73 per cent of Australian grandparents are regularly involved in taking care of their grandchildren and are on call when they are needed.

They will alter plans with friends and rearrange holiday and travel arrangements to be available to provide care for their grandchildren and support their children in their child-rearing responsibilities.

As our population ages, we will see even more grandparents on the school run, in the playground, pushing prams and taking kids to after-school dance class and soccer training.

Grandparents Day is a fitting moment to acknowledge the big social contribution grandparents make.

Why have grandparents become so much more important to families day-to-day?

There are several factors.

Lower fertility and fewer children means families are smaller and family networks are narrower.

Life is more expensive than for previous generations, both parents often work and paid childcare can be costly.

To fill the gap, modern grandparents often step in to provide day to day support and offer unconditional love and security.

In the UK, it is estimated 60% of childcare provision is provided by grandparents, and in the US grandparents and family carers save the government more than $6 billion in childcare costs each year.

From an economic perspective alone, grandparents deserve to be celebrated.

Nearly all grandparents who regularly spend their time helping take care of their grandchildren agree that contact with their grandkids has positive outcomes for their health, but healthy contact with grandchildren doesn’t need to be every day.

While 22.9 per cent of Australian grandparents fill the pivotal day-to-day role of driver, chef and full-time babysitter for their grandchildren, there are also long-distance grandparents (23.8%), casual grandparents (12.7%) and old fashioned ‘Grandbuddies’ whose time with their grandkids is all about having fun (32.9%).

There are, of course, grandparents who have raised their families and love their grandchildren, but may no longer be able to play a hands-on caregiving role due to age or ill health.

Other grandparents love their grandchildren but want to make the most of the freedom retirement offers without the responsibilities of child rearing.

Some much-loved grandparents may have already passed away.

Each and every one of them can be celebrated for their unique contribution this Grandparents Day.

Let’s not forget that grandparents can be celebrated every day of the year, not just on October 28.

The best way to thank grandparents and surrogate grandparents for all they have given is to offer the gift of your time.

Even if grandparents have busy lives of their own, why not invite them to weekly family meals, end of year dance revues, sports events and family holidays.

For those at a distance or are no longer able to be hands-on as caregivers, schedule regular visits, Skype sessions and phone calls. In a world where social isolation is a key issue for seniors, nurturing relationships is so important. Countries worldwide - Canada, Estonia, France, Germany, Italy, Mexico, Pakistan, Poland, Singapore, Spain, the UK, the United States and elsewhere – recognise grandparents’ essential roles in modern family life.

This Grandparents Day, let’s join them in celebrating the great contribution Australian grandparents make to our lives.

National Grandparents Day, Sunday, October 28

Stig Andersen is IRT’s Executive General Manager - Retirement Villages

READ MORE, John Hewson: The end of government by major parties?