So, just looking at it what you are trying to do is build a relation from your “Date” table to your “Слово дня” table, using the current date, yes?
Firstly, using the Format Date plugin to obtain the current date is problematic. That plugin is known to be buggy and unreliable. A better method is to just use a math column with the “Now” special value.
And then those extra columns you had with the split/splice/etc were never going to work reliably.
Given that you’re wanting to find records that fall within “Today”, all you really need to do is use an if-then-else column in your “Слово дня” table that returns “true” if the date is within today. And then use that if-then-else column to create the relation.
I’ve made the adjustments in your app. Take a look and let me know if you have questions.
Just as a side note, you have the app privacy set as “Public with Email”, but you don’t have User Profiles configured. You should fix that, otherwise you’ll have more problems as you progress with the app.