Alright. Let's do this again
It's ultimately the translator's choice, what exact words to use, so going for
yanqolat is, I guess, possible. There are problems with that, though. "To collect" (or "to gather") is an idea fundamentally applied to plural objects and uncountables. I guess you can, in English, say "I collected a penny", meaning that you picked up a penny (~"added a penny to my collection of money?" - or is that singular use reserved exclusively to debt collecting?). Nevertheless, this is an extension probably not shared in Dothraki. To make matters worse, Dothraki is not as explicit with plurals as many languages, so pushing for the unusual singular use is even harder. As "a day"
asshekh is animate, so there's a notable difference in plural, but
asshekh has inanimate use too, as "today", so the reading would go easily there. Not that this would make any easy sense either, as "today" is fundamentally a singular event, but you might approach it as an uncountable, a mass noun, a waterlike puddle of now. And you could certainly be misled and confused.
Putting
asshekh to allative is a whole another matter. Objects in sentences are in accusative, if there is no special reason for some other case. We know that
yanqolat supports one special use of another case than accusative. You can use ablative to mark the fact that only some of something was collected, not all of it ("Anha yanqo korikh" - "I gathered the sticks" vs. "Anha yanqo korikhoon" - "I gathered some sticks"). What would allative mean here? Dunno. Maybe if
asshekh were a complementary argument, allative might denote to the place where you gathered something ("gather the sticks
in that corner") or the resultant collection of gathering ("gather the sticks
into a pile"). Perhaps you might expect the main object of the sentence elided, resulting in something like "collect into a day".
I would go with
qoralat as it feels pitch perfect to me. For true YOLO attitude
qorasolat would work too. We have "to seize" as one translation for
qoralat, but this is probably in part due to a bit misleading dialogue translation from the series:
qoralat most likely does not explicitly denote to the act of taking, it denotes to holding, to keeping, to having.
Qorasolat is the word explicitly denoting to taking, to making something your own. This has some rather dark undertones, though, as Dothraki are so fond of working on their own terms, so fond on abusing the priviledge of the stronger. The meaning of qorasolat extends from simple act of taking all the way to rape. And what would be more YOLO than "Abuse the day on your own terms with complete disregard to the damage you do to others."
I would go with informal imperative, as I view this more a suggestion than a straight out command. Depends on the take.
Why
vosma? Of course "but" works just fine, considering the meaning of the phrase, but even your own translation of your Dothraki translation uses "and". The latin does not use any conjunction (quam looks like a conjunctive, but if I'm not mistaken, it's just a part of an argument "quam minimum"), so you might even try to do without in Dothraki too. On the other hand, in my personal feel, plentiful use of conjunctions fits Dothraki, and I like to often use the complete precede-both-sentences system. That would not be wrong here, and in my opinion would nicely preserve the parallel sentiments feel of the original. The weak connection of the original gives me a feel of two independent but resonant sentiments, while "and" in the middle leans slightly on the "and consequently" direction.
Yes,
ray for "to have" is decidedly wrong. English uses "to have" as an auxiliary verb for perfect tense (expressions like "I have x'd the z"). Dothraki uses auxiliary not-even-really-a-verb
ray for similar expressions, but this has very little to do with what "to have" otherwise means in English. We saw before that
qoralat can be translated as "to have". There's also an expression
mra qora, literally "in hand", eg. "
Korikh mra qora [anni]" - "I have a stick".
Trying to go "want little, hope little from tomorrow" does not does not seem a bad idea, but it's not easy, so why not use
shillat, "to trust"? I would not say it's certainly the right kind of "trust" word, but seems very promising and straightforward.
My attempt would be, I guess
Ma qoras asshekhes, ma shillas silokh zolle.
You might drop the animate accusative from asshekh, and move it from "a day" to "today", as that's pretty much what's implied anyway, and the phrase would be more symmetrical, but, dunno, I kinda like the asymmetry and the indirect sense the
asshekhes gives.