Missing of Flight due to Departure Time Changes

We booked our tickets via the KLM website in June 2017 to visit the Netherlands in December 2017. At the time of our booking departure stated 11:30 pm on the 26th of December, thus meaning arrival on the 27th of December. Upon printing our tickets prior to going to the airport, we noticed that it indicated 12:30 instead of 11:30 on the 26th of December, so we arranged to arrive an hour later for departure. In essence it meant 00:30 on the 26th of December a whole day earlier that 11:30pm of the 26th of December as originally booked, which is something we did not take notice of and also was not made aware of by the airline in any way. One would think that when running an international airline that you would be clear and informative towards your international travelers with regards to daylight saving time adjustments and how this could/ would affect their flight plans. We would never have been able to make the 00:30am flight as we planned and booked for leaving pm the 26th of December, even our visas only allowed entry into the Netherlands from the 27th of December, not the 26th. This meant that we had to pay and 300 Euro per person for new seats (4 people, even though my 19 month old was sitting on my lap). When we asked if this is a regular thing, the attendant at the desk said, my dear you're the 5th family tonight that this has happened to and while we were queuing to pay for our new tickets another family arrived after us whom also made the same mistake. This is apparently a very regular occurrence with this specific KLM flight and no attempt was made to any of the parties affected (not even by the ones who made use of travel agencies)to bring the time change and it's travel implications to their/ our attention. After coming back from our holiday and discussing what happened to us we realized that this has happened to alot more people and has been brought to KLM's attention before and still nothing has been done to make travelers more aware of the small time change which in effect makes your flight a day earlier than what you planned to depart. I looks like a sneaky way to catch out unaware travelers and make a huge amount of money of now desperate travelers. You should be ashamed, it's ****************. This incident started off our first overseas holiday as a family in a very bad way and we will be sure never to make use of or promote KLM airways to any of our friends or families.