1) The 13th day of the month of Adar is known as Taanis Esther, the fast of Esther.
This fast day is in commemoration of the Jews' gathering on that day [in Teshuva and prayer] in preparation for defending themselves against the imminent threat of their annihilation at the hands of their neighbors at the behest of Haman and Achashveirush.
The fast was established as a reminder that Hashem always sees our individual [as well as our collective ]suffering, and will always come to our rescue if we return to Him with all our heart, as the Jews did at the time of the story of Purim. (Mishna Berura Siman 686:2)
2) This fast is not as stringent as other fast days, and in cases of necessity (such as pregnant or nursing women, or people with certain other hardships or non life-threatening sicknesses) one need not fast.
However, one who can fast, should not simply dismiss this fast and be different than the rest of Klal Yisroel. (Ram"a 686:1)
QUESTION & ANSWER CORNER:
(Reader Submitted Questions of interest (on topics related to Halachos we covered, as well as other interesting topics) and my Answers taken from the Q & A page on the Halacha For Todaywebsite. For study purposes only, NOT for Psak Halacha. Questions can be sent to Halacha For Today)
Reader's Question:
A certain question came up [a while back]concerning peeled eggs, onions and such [which may not be used if left overnight, unless something was added to it]. I have a product in my fridge called "All Whites" 100% liquid egg whites certified by the O.U. By the nutrition facts the ingredients read: 100% liquid egg whites. It appears that nothing has been added, just the yolk has been taken away. Would this be considered as leaving eggs with out the peel overnight? I haven't used it yet but some people in my family did, if its a problem what should they do?
My Answer:
According to Rav Moshe Feinstein Zatzal, there is no problem at all with eggs that were manufactured specifically to be used for extended periods of time (such as for commercial use or in your case a container of eggs meant to be stored and used for more than one use) and you may safely eat them and not worry about any danger.
Only if you crack or peel an individual egg and leave it overnight is there a reason for concern. (Igros Moshe Yoreh Deah Vol. 3 Siman 20)
Our holy sages, the Chazal tell us
תנא דבי אליהו כל השונה הלכות בכל יום מובטח לו שהוא בן עולם הבא, שנאמר הליכות עולם לו, אל תקרי הליכות אלא הלכות - one who studies [at least two] Halachos daily is assured a portion in Olam Haba - the world to come. (:מגילה כ"ח )