Are you aware that dates does not get influenced by timezones, right?
And not only that:
Thursday was January 31.
Friday was February 1.
Saturday was February 2.
We need to find out the date the original poster actually entered to make the booking. They may have entered 2/2/19. Perhaps the code for the calendar interpreted it literally (as year 0019) while the code to display the date string did a conversion for Y2K.
> Are you aware that dates does not get influenced by timezones, right?
Yeah, but the situation is worse than that. Weeks boundaries are influenced by a locale. What is the first day of the week? Sunday? Monday? I know that in russia a week starts with a monday. I know also that in en locales it is not the case, I was never able to understand english calendars, so the very first thing I do is fixing locale to see a "proper" calendar which I can understand.
Notice that there are no hints where is sunday and where is monday, you make a decision what is what based on data layout in a two-dimensional grid. For example, I read the screenshot in the tweet as Feb 2 is a Friday, not Thursday.
This leads me to a hypothesis what happened with AirAsia. They messed up locale dependant calculation of a week boundary. Like they added 1 instead of subtracting it, or maybe they applied the locale dependant shift of a week bondary twice, or made some other software bug like that.