The best time to start a savings plan is as soon as you can afford to do so, without over-committing yourself. The reason for this is simple – the earlier you start your savings plan, more money you will have in retirement, because it’s been invested and growing for a longer period of time, and because you got into good savings habits sooner.
Don’t wait until you’re older to start planning for when you’re older – start as soon as you can, even if you’re starting with a small monthly amount. You can always save more in future as your income grows – and getting into good savings habits as soon as possible will make you significantly wealthier over time :-)