I want to share what I know on the subject. Let's start with the place where his feet are growing in this matter, namely the treatise PEA Jerusalem Talmud (chapter 8, page 37-B):

רבי חנינא בר פפא הוה מפליג מצוה בליליא חד זמן פגע ביה רבהון דרוחי 'א"ל לא כך אולפן ר' (דברים יט) אל תסיג גבול רעיך א"ל ולא כן כתיב (משלי כא) מתן בסתר יכפה אף והיה מתכפי מיניה וערק מן קמוי

Rabbi Hanina bar Papa separated tzedakah night. One began to annoy (his) head (evil) spirits. Said (it) to him (p Hanina.): "Do not you taught Rabbi (in the Torah): Do not push back the boundaries of thy neighbor"? I said to him (p Hanina bar Papa.): "Is not it written:" The gift in secret extinguishes the wrath "And (then the spirit) twisted away from him and ran?.

From this point it is clear that the separation of tzedakah night evil spirits is regarded as an encroachment on their territory. Why? Because the night - a time when evil spirits organize fulfillment harsh sentences. Arizal says:

כי בערבית זמן דין גמור ואינו זמן הראוי לתת צדקה

Since in the evening - (there is) a full court, and is not suitable time (is) giving tzedakah.

That is, evil spirits, were each sentenced to a person already decide how best to fulfill, and a man spoils his tzedakah. We know that tzedakah cancels harsh sentences. It is logical that quite the contrary is necessary to give tzedakah night. However, as I see the logic in this so - give tzedakah during the day, and once again not to conflict with evil spirits, so they are not annoyed once again.

However, Rabbi Hanina bar Papa was not one of them and said that tzedakah, this secret (and the night is a time when everyone is asleep and can not be afraid of extra eyes) neutralizes anger. And judging by what happened next - anger extinguished completely konktretno acts on evil spirits - they begin to keep their distance.

Why did Arizal said that better not? Probably because we are not quite to the level that Rabbi Hanina bar Papa. And do not take any chances. And then I want to note that in the Talmud, in the case of p. Hanin it is not a transfer of tzedakah in the hands of the poor, and the secession. That is, Rabbi Hanina opened the purse, looked, how much money he has available, and from them set aside some portion and defined them for the needs of the poor.

And what the Talmud says about the immediate transfer of money to the poor? Here's what:

אם נתת פרוטה לעני שחרית ובא עני אחר ועמד לפניך ערבית תן לו

If you gave the rod (a coin) to the poor in the morning, and come after the poor and stand in front of you in the evening (it) let him.

This is a quote from chapter 3 "Pirkei Avot of Rabbi Nathan." And then a direct order - to give tzedakah night, when poor stands and requests. This chapter, by the way, is summed up with the words:

וצדקה תציל ממות

And Tzedakah saves from death.

And the same thing we see in the case described in the tractate Shabbat 156-B:

דר''ע הויא ליה ברתא אמרי ליה כלדאי ההוא יומא דעיילה לבי גננא טריק לה חיויא ומיתא הוה דאיגא אמילתא טובא ההוא יומא שקלתה למכבנתא דצתא בגודא איתרמי איתיב בעיניה דחיויא לצפרא כי קא שקלה לה הוה קא סריך ואתי חיויא בתרה אמר לה אבוה מאי עבדת אמרה ליה בפניא אתא עניא קרא אבבא והוו טרידי כולי עלמא בסעודתא וליכא דשמעיה קאימנא שקלתי לריסתנאי דיהבית לי יהבתיה ניהליה אמר לה מצוה עבדת נפק ר''ע ודרש וצדקה תציל ממות

I was the daughter of Rabbi Akiva. They told him the Chaldeans (astrology): in the day when she will rise into the wedding hall, will die. It was (b. Akiba) is concerned with these words. During the day she pulled out a hairpin and stabbed (the wedding day) into the wall, accidentally hitting the snake eyes. In the morning I went to take the (hairpin) - saw the snake. I said to her father: What did you do (such because of what you have saved from the snake)? Said to him, before it came to the door of the poor and the evening meal were all busy and no one paid attention to him, and I gave him a piece of food. I told her (p. Akiva) "will make you a commandment!". Rabbi Akiva came and explained (this case): "And Tzedakah saves from death."

In this story, again important that tzedakah was transferred to the evening and nothing terrible has happened. On the contrary - a terrible did not happen due to the fact that tzedakah was given in the evening.

Here again we can say that Kabbalah night tzedakah is undesirable because of the processes associated with the execution of the harsh judgments. But this is the answer to p. Ovadia Yosef:

מותר גם לפי הקבלה לתת צדקה בלילה, ושאין מקום להקפיד בזה

(שו"ת יביע אומר חלק ט 'חלק יורה דעה סימן טו)

Allowed also from the words of the Kabbalah give tzedakah night, and there is no place in this ustrozheniya (no need ustrozhat in this case).

Once a wise man said that Kabbalah is not opposed in principle to give the night possible. Although the question offices (no transmission) tzedakah night, you need to think: Maybe you need to beware and to postpone this important matter in the morning? However, if you need come in the evening and asks what to think and not be afraid - it is imperative to fulfill the commandment of tzedakah, even at this time.