There is a lot more skipping it than upholding it. 
You need to scrap this misinformation as it NOT strictly correct…
May 1st in the UK is May Day and sometimes (not this year as it will be May 5th) it ties in with it being a Bank Holiday. Therefore it is NOT technically “just another day”.
How is it misinformation? Those nations celebrate on every May 1st every year unless it falls on a weekend then it’s the first Monday and some of them have done it since the mid 1850’s, from my checks the UK always celebrates on the First Monday of May so completely different and they have only been doing it since 1978
Because as I said, we know it here as ‘May Day’… regardless of the fact (as is the case this year) that sometimes it’s not actually a public holiday or as we call them here, a bank holiday.
Therefore to call it “just another day” (to quote the wording of title of the graphic in the original post we are discussing) is in itself, a form of misinformation.
Naturally I can’t comment about other parts of the world shown on the map, as I don’t live there.
As for it only being the way you described since 1978, I have not much I can say about that as I was only 2 years old at the time! 
Traditionally in Norway for example the 1st of May has the designation National Labour Day, and the point is to mark a symbolic respect for the day. But my impression is that the day itself as a symbol has faded off at least a little bit. It has not got the same standing as it used to have in the general population. That is at least my modest personal impression. 
Yes I think you are right about it fading, in terms of significance. Over here, we don’t have it as ‘Labour Day’ just ‘May Day’, with or without it as a holiday, depending upon timing of said holiday (as @shyguy rightly pointed out, by the way).
I’m not saying the UK don’t celebrate May Day, All I’m trying to say is that those countries celebrate on the 1st of May every single year no matter what weekday it falls on, The Uk do it on the first Monday of May every year so the date will be different every year, so unless the first Monday in May is the 1st, the actual day May the 1st is treated like “just another day” in the UK and other places that don’t celebrate on the actual day itself
I hope I have made myself a little clearer this time
The official system in USA is Metric as well just nobody uses it.
If it’s official they should start replacing all their signs along the roads
How DARE the chart (notice I am not directing this at YOU personally) call us British “liars”. We actually use BOTH measurement systems, depending upon the circumstances thereof. 
if you want a flight ticket to
Krung Thep Mahanakhon Amon Rattanakosin Mahinthara Yuthaya Mahadilok Phop Noppharat Ratchathani Burirom Udomratchaniwet Mahasathan Amon Piman Awatan Sathit Sakkathattiya Witsanukam Prasit
in thai
กรุงเทพมหานคร อมรรัตนโกสินทร์ มหินทรายุธยามหาดิลก ภพนพรัตน์ ราชธานีบุรีรมย์ อุดมราชนิเวศน์ มหาสถาน อมรพิมาน อวตารสถิต สักกะทัตติยะ วิษณุกรรมประสิทธิ์
it would be easier you say bangkok.
