What is the ruling on breaking the fast while mistakenly believing dawn has not broken or sunset has not occurred?

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If one breaks the fast believing that the dawn has not yet appeared, but it has, or if one breaks the fast believing the sun has set, but it has not, the fast is invalidated (the person is considered to have broken the fast). Regarding the continuity of the sequence (Tatabu'), there are two interpretations: first, the continuity is not broken because the breaking was due to an excuse (error of fact). Second, the continuity is severed because the action resulted from a mistake, similar to one who thought he had completed two months but discovered otherwise.