Related על ראש השנה 3:1

If they sanctified him in his time, and it proves that the witnesses were false, behold, it is sanctified. If they have sanctified it at night, it is not sanctified. If they lead him under duress, by mistake, on purpose, or astray, behold, it is sanctified. Have they sanctified it before its time or after its lengthening - [that is] less than days or more than days - can it then be sanctified? [there is a] teaching [of Scripture that] says ”Month [beginning]” - there is no month [beginning] before the 30th day.