The facilities provide seating, toilets and vending machines, as well as staff offering tickets and information.
But a decision was taken last month to close the terminal buildings between 10.15am and 3.30pm due to a lack of funding.
The move h
as left passengers, including out-patients making their way between Sheriffhall and the Royal Infirmary, exposed to the elements in the middle of the day.
The Sheriffhall facility is run by Midlothian Council while the Straiton park-and-ride (pictured) is a City of Edinburgh Council concern.
A Lothian Buses spokesperson said funding to staff the terminals was provided by the local authorities and added: "Due to the current financial climate we can not afford to man the terminals outwith peak hours."
News of the amended operating hours did not prove popular among bus users in Dalkeith.
Mayfield's Irene Bruce (61), retired, said: "It should be open all day, it shouldn't just be open at peak times.
"It's handy to go there because in Edinburgh you can't park anywhere."
Andrew Des (32), who works for NHS Lothian, said: "It's not very good. Especially the one at Sheriffhall, which is on the bus route to the hospital. And we're coming into winter time as well."
Sandra Watson (64), retired, of Dalkeith, said: "I thought when they launched the facility it was to be open when people finished, because people at the infirmary have different shifts."
A spokesman for Midlothian Council said: "We always aim to target finite financial resources so as to achieve the greatest benefit to the public at the lowest possible cost to the taxpayer.
"We will review funding options for next year during the council's budget-making process."
A spokesman for City of Edinburgh Council said: "Lothian Buses' previous experience of running park-and-ride facilities has helped them to identify when best to have staff on site.
"Providing staffing outwith peak times would not be an efficient use of tax payers' money."
The terminal buildings are currently open between 6.45am and 10.15am and 3.30pm and 7pm each week day.
