Adelaide commuters will get a free day of travel by bus next week after an IT glitch led to hundreds of people being overcharged for bus tickets.
The error was caused by new ticket validators not switching over to daylight saving time.
Phillipa Goode took the bus from Norwood at 9.30am this morning and is potentially one of hundreds overcharged for her ticket.
"It's a bit strange, you think they could work that out," Goode said.
"I'm sure they can update the machines to work with daylight saving."
The IT blunder involved new tap and pay machines on all of the state's 750 public buses, which didn't switch over to the correct time when daylight saving kicked in.
Matthew Bowman from the Department of Infrastructure and Transport said it was an unusual situation.
"That's why we're looking closely to find out what's gone wrong here and make sure it doesn't happen again," Bowman said.
Off-peak rates are meant to start from 9:01am on weekdays.
While the clocks went forward an hour on Sunday, they did not on bus ticket validators.
This resulted in some commuters being charged at peak rates until 10am, meaning they paid between 30 cents to $1.85 more than they should have for a one-way fare.
In the afternoon peak period some commuters may have landed a cheaper fare.
"We really apologise to customers for this issue," Bowman said.
All commuters are set to have a day of free travel next week network-wide in the way of an apology.
It is an error expected to cost the government hundreds of thousands of dollars.
The free travel day is yet to be finalised.
Despite learning about the problem on Tuesday, hundreds of buses still had machines with the incorrect time today and the department eventually rolled out a software update this afternoon.
"If that doesn't work we'll be manually updating those in the next day or so," Bowman said.
O-Bahn, train and tram tickets were not caught up by the IT error.
The department is now in the process of contacting affected ticket holders to reimburse them.
It is also asking anyone concerned to call them.
