Within fifteen (15) calendar days after ...

Within fifteen (15) calendar days after ...
 

Hello, foreros! This is my very first post. I stumbled upon it while searching for "a más tardar" in Google to find examples of syntax. Hopefully this is the right place to ask this.

I'm translating a policy document for a school district which includes the above phrase several times. I want to vary it, instead of saying it the same way every time. Please let me know if the following are ok, or please make corrections and any other way that sounds good in Spanish to say it. Also, which one sounds the Best (even though I might also add variations). Thanks! I'm looking forward to see how well this forum works.

En quince (15) días calendarios o menos de recibir la apelación
A más tardar en quince (15) días calendarios después de esta reunión
Dentro de quince (15) días calendarios de recibir la respuesta
En quince (15) días calendarios o menos a partir de dicha reunión
Dentro de 15 días calendarios después de recibir una solicitud por escrito

All of them seem correct for me, except:
"Días calendario": no plural for "calendario"
And I would also avoid "(15)". It's either number or letters. :)

Thank you. Some of them didn't sound all that great to me, so I wanted to check with some native speakers.

As for the correction of días calendario, thanks. I also found that I can also use días naturales for variation.

I'm keeping the "quince (15)" because it's legaleze. Unless it isn't done in Spanish legaleze as it is in English??? In that case, I would think that the spelled-out word would be more formal, if I need to choose one or the other.

Yes, you should write "quince", not "15". Much more formal, in Spanish. There are "días naturales" (from Sunday to Saturday) and "días laborables" (from Monday to Friday or Saturday). :)

Legal documents I've seen in Spanish only use number names.

"Días laborables" are also "días hábiles" in Mexico.

Also you could to use Dias posteriores in the sentence.
or maybe dias habiles could works too.

Within fifteen days the calendar after gets the solicitude by wrote.
Dentro de 15 días calendarios después de recibir una solicitud por escrito

I don't know if first goes solicitude by wrote or written.
Or I need to exchange wrote solicitude.

I'm looking forward the sentence correct.

Thank you, everyone, for all your replies. :rose:

The original English is: Within fifteen (15) calendar days after receipt of a written request ....

A few corrections to your English, if you don't mind. That's what we're all here for, right?

I don't know if solicitude (request is better) should be first, or wrote or written.
Or do I need to switch the order of wrote and solicitude?

I'm looking forward to the correct sentence.

I appreciate the comments re días hábiles/laborales. It is a good reminder for me. However, I cannot use these terms in this context, because these refer only to working days. That's why I am using días calendario or días naturales. And now I see that I can also use días posteriores. Let's see:

Dentro de los quince días posteriores del recibo de una solicitud por escrito.... ok?

@mrb: You can't use "días posteriores" without making clear they're "días naturales"/"días calendario", because, as you said, it's "legalese". That's for less formal documents.