As Japanese Zen Master Dogen said in Genjō Kōan:
We get nostalgic when the blossoms wither but hate it when the weeds blossom.
This is a typical example of The First Noble Truth. We look at the beautiful cherry blossoms and morn their transience. We get attached to the experience of beauty and want it to go on forever. But because we know it won't last long we get nostalgic even before they wither. And once they actually dry up and fall, we feel the sadness. This is an example of attachment-based-dukkha.
At the same time, when the weeds grow high in our yard, when they thrive and bloom - we do not feel the joy of beauty. On the contrary, we feel joy when the weeds wither and die. We'd rather kill the weeds with a lawnmower or a herbicide chemical than see them flower. When the weeds thrive despite our efforts to kill them, we feel frustration. This is an example of aversion-based-dukkha.
In both cases, a plant grows flowers which bloom and then eventually wither and fall. But we think that the cherry blossoms are good because they are beautiful and the weeds blossoms are bad because they are ugly. It is our attitude (aka "attachment") that determines whether we experience dukkha or not. But what is the nature of this attachment and how can it be removed?
If you look at your mind directly, you will see that you have this fixed preconception - "holiday is good and work is bad, because _______". Just like with flowers and weeds. You need to look at your mind directly and see the formula that you are stuck on, e.g.: "work is stressful, because at work I'm continuously bombarded by endless requests and don't have time to even use the toilet" - or something like that.
These type of formulas often come from some implied social stereotypes that we subconsciously absorb from the social interactions. For example, if most people around you assume that hard work is for dummies and that the "smart/successful" people do not work much, you may internalize this attitude as "hard work is for losers" - which may lead to the kind of aversion to workdays and attachment to holidays you're talking about. The exact formula will be different for everyone, but there is always some kind of formula involved, you just need to see what it is.
Once you see your formula directly, you can get rid of attachment/aversion by simply letting go of the formula. If your vipashyana is not strong enough yet to do it directly, you can use a counter-fabrication like seeing peace in effort and stress in rest - or as Buddha have said, "see doing in not-doing and not-doing in doing". In other words, you can analyze the two situations (holiday-time and work-time) upclose, find the elements that go contrary to the attachment, and upadana those element-signs - to fuel the counter-fabrication by going over the signs again and again.
An internalized preconception - what I called "the formula" - is an example of reification at play. We generalize some description ("There is a hard line dividing weak and successful people => The weak people are forced to work a lot => The successful people are smart enough to avoid hard work => Overtime work is for dummies => If I work overtime, I'm a loser => Attachment to holidays, feeling stressed when there is work on weekends => Dukkha") and then we reify this description into a wordless formula that contains all of that description in a highly condensed form. Every time we think about working overtime, we feel stressed, with the entire description quickly replaying in our heads.
The technique that Buddha taught -- "seeing the non-pleasant in pleasant and seeing the pleasant in non-pleasant" and "finding the not-doing in doing and finding the doing in not-doing" -- works by breaking the generalizations we make about the components of the formula. We can attack the formula that "Overtime work is for dummies" by finding factual evidence that makes the formula false, for example: "Successful people actually work a lot, they work crazy hours - in fact, that's how they become successful!" -- Here, we have found an example that goes contrary to the generalization we have internalized (that "Successful people do not work hard"). By thinking about this counter-fabrication over and over again we can weaken the original reification and destroy the formula that leads to suffering.
Or, in the other example, one where "I" felt that "work is stressful, because I'm continuously bombarded by endless requests" - we could approach it like this: "Why do I think that being bombarded by requests leaves no time for anything else? Indeed, it is up to me to control my work pace. Why don't I slow down a little to make it more comfortable?" In this case the unquestioned generalization was the formula that "being bombarded by requests leaves no time for myself". We have internalized an assumption that we must handle every request as soon as possible, with no regard to our own comfort level. Identifying and deconstructing that assumption allows us to change our behavior and our perception of the situation - eliminating the source of aversion that leads to suffering.
Holiday is holiday and work is work - but you don't have to love one and hate the other. You can learn to be at peace in the suchness of here-now, whether it's work or holiday. You just need to understand how dukkha comes from reification and how reification can be dispelled by challenging one of it's underlying assumptions.