Obligation of Tearing Garments at the Western Wall on Friday Afternoon
Question
Answer
It is necessary to tear garments until one accepts Shabbat (many do not tear, but there is no source for this).
Source
The Pitchei Teshuva, Yoreh De'ah, Siman 340, Se'if Katan 1, cites from the responsa of Givat Shaul that one should rebuke and reprimand those who are lenient on Friday during the seven days of mourning by sitting on the bench and wearing shoes immediately after midday out of respect for Shabbat, and their custom should be annulled. In Shu”T Shivat Tzion 20, it is stated that at the moment the community accepts Shabbat, meaning at the recitation of 'Baruchu', mourning ceases.
Therefore, regarding the law of tearing, one should not be lenient after midday, except when the community has accepted Shabbat. In our times, when there is no community to follow, from the time one accepts Shabbat, one is exempt from tearing.
Those who do not tear, the Chazon Ish said that this custom has no foundation, and there are those who justify the lenient by saying that if one wears Shabbat clothes, and if they tear them, they will not have good clothes for Shabbat, it is possible to be lenient.