Mishnah Berurah — משנה ברורה

While it is still day - But if one delayed in donning [their טלית] until it was nighttime, they should not make the blessing anymore, because maybe the law follows the Rambam. And it seems from the Magen Avraham in se'if katan 4 that even during twilight it is permitted to recite the blessing up until nightfall. And his reason is that regarding ציצית it (ie. the verse) does not say "day", [rather] it just says "and you shall look upon it" - it's inferred to mean "as long as we can see it". The author of Derech Hachaim ruled this way as well. And I saw that the Mateh Efraim is stringent regarding this. However, if one is in doubt about this, whether twilight arrived yet, it seems that one may certainly make the blessing [on their טלית], for even without that, the opinion of Tosefot and the Rosh are that a daytime garment is obligated [in ציצית] at night (and so according to them, you would be obligated to make a blessing at night). And the Gr"a in his commentary also leans towards this opinion. See there further.