What is the ruling on one who has intercourse with his wife during the daytime in Ramadan, while she is not forgetful and is fully aware and conscious of the situation?

A conditional divorce takes effect as soon as the condition is met, even if the husband is unaware of it. As for the رجعة (reconciliation/revocation of divorce), it does not occur through mere words without intention, but it does occur through intercourse during the waiting period (iddah), even if the husband was unaware of the divorce having taken place. The wife must inform her husband that the divorce has occurred.