The Kitáb-i-Aqdas - The Most Holy Book
Index term: short (third), under Obligatory Prayer(s)
n5.
at noon and in the morning and the evening
Regarding the definition of the words "morning", "noon" and "evening", at which times the currently binding medium Obligatory Prayer is to be recited, Bahá'u'lláh has stated that these coincide with "sunrise, noon and sunset" (Q&A 83). He specifies that the "allowable times for Obligatory Prayers are from morning till noon, from noon till sunset, and from sunset till two hours thereafter". Further, 'Abdu'l-Bahá has stated that the morning Obligatory Prayer may be said as early as dawn.
The definition of "noon" as the period "from noon till sunset" applies to the recitation of the short Obligatory Prayer as well as the medium one.
q81.
 
Question: Should the third Obligatory Prayer be offered while seated or standing?
Answer: It is preferable and more fitting to stand in an attitude of humble reverence.
q86.
 
Question: At noon, which is the time for two of the Obligatory Prayers -- the short midday prayer, and the prayer to be offered in the morning, noon, and evening -- is it necessary in this case to perform two ablutions or would one suffice?
Answer: The renewal of ablutions is unnecessary.