You better check your timetable before leaving the house this week as more than 9,000 new weekly train, bus and ferry services launch for the Greater Sydney network.
The Illawarra, Central Coast, Blue Mountains and Hunter have new bus and train timetables and regional trains will also be affected throughout New South Wales.
Premier Gladys Berejiklian said it would be the "largest timetable change in one go" for the state.
"If you haven't used public transport today, the timetables obviously kick in today but tomorrow will be the real test. Please make sure you look up the app or the information we have so that you're not caught out if your service has changed."
"This is a huge shift in the way in which people can move around our greater city … chances are in more than two-thirds of our stations you'll cut your waiting times by half."
Transport Minister Andrew Constance said the changed timetables would simplify the transport network, increase capacity and deliver more services.
More changes for some commuters
But the Opposition said the changes would mean increased travel time for some commuters and some lines that skip stations.
"The Blue Mountains' trains no longer stop at Redfern, we know that the western line for instance from Auburn to Central will take 11 minutes longer," Opposition transport spokeswoman Jodi McKay said.
The State Government claimed the benefits of increase in services outweighed the negatives.
"In some cases there will be interchange points across the network, and it's vital that people plan their trips," Mr Constance said.
"But overall, I believe everyone is set to benefit from these major changes."