Translation:It is enough for today, I am tired.
I'm no expert, but I think that in terms of time para is more specific. If you were saying "Voy a comer para las seis" ("I am going to eat by six", not sure why that's the sentence I thought of...) then you'd use para, since you're eating by a specific time. In this example, it's enough for today, so that's not very specific. It's enough for the whole day, not a specific time. I'm not sure if I'm making myself clear, so to summarize: Use para if something's happening by a specific time (or day or week or year, etc.) and use por if something's happening around some general time frame.
I answered this same question in another thread. I'll paste it here too. Hopefully it helps.
The technical answer is comma splices are not grammatically correct in Spanish either. You can look at the RAE (Real Academia Española) grammar rules regarding comma usage (http://www.rae.es/dpd/srv/search?id=V1EqcYbX4D61AWBBrd) for the specifics.
That said, it is exceedingly common to see comma splices in Spanish. I've asked a few native speakers about this topic before and most of them said they see nothing wrong with joining two independent clauses with a comma. So, it is definitely not stigmatized in Spanish like it is in English.
Another similar case is the vocative comma. You will rarely see it in actual written Spanish, but it is technically required.
I think a good parallel to this in English is the sentence "Who do you want to give that to?" Technically, that sentence is not grammatically correct, but it is still used every day and it is much more common than the actual grammatically correct version. Many native English speakers probably wouldn't even recognize it's wrong.
Thanks Mikey. I guess we should be correcting the comma splices in our Immersion translations - I've been mainly keeping the original punctuation unless I rearrange the clauses of a sentence. But if it's not stigmatized in the original language, we should correct it when translating to a language where it is stigmatized.
Are there cases where this more accepted than others? Right now, I'm seeing it used a lot in a lesson about negative imperative statements combined with an explanation for the negative imperative statement (No vayas a esa tienda, es muy cara). So this got me wondering if usage of the comma in this way is more common in certain circumstances. Thanks!
I would say the sloppiness to which you refer is rampant in Spanish, even by those who are teachers and have doctorates.
Another of my pet peeves - in newspapers, there seems to be an on-going contest to see who can write the longest but still intelligible sentence. I would say the average length of a sentence in a serious article in a Spanish newspaper is twice that of an English sentence. Thanks for listening :-)