Kiram reported that he told Imam As-Sadiq (a.): “May my life be sacrificed to you, i decided to fast until the Riser (Qa’im) rises, God is quickening the salvation through him.” He said: “Fast, but do not fast on the journey, nor on the two festivals, nor from the 11th to the 13th day of Dhu-l-Hijjah, nor on the day when there is doubt that it is one of the month of Ramadan.” [At-Tadhib Al-Ahkam, Volume 4 page 233 Hadith number 58]
عن كرام أنه قال للإمام الصادق عليه السلام: إني جعلت على نفسي ان أصوم حتى يقوم القائم عجل الله فرجه فقال: صم ولا تصم في السفر ولا العيدين ولا أيام التشريق ولا اليوم الذي يشك فيه من شهر رمضان
From Muhammad bin Muslim, from Abu Abdillah (s.a) who said: “If a person travelled in the month of Ramadan, so that he went out after noon, then he is responsible for fasting on that day and he associates it with the month of Ramadan.” [Wasail-ush-Shia, Volume 10, Page 191]
محمد بن يعقوب ، عن محمد بن يحيى ، عن محمد بن الحسين ، عن صفوان ، عن العلاء بن رزين ، عن محمد بن مسلم ، عن أبي عبدالله ( عليه السلام ) قال : إذا سافر الرجل في شهر رمضان فخرج بعد نصف النهار فعليه صيام ذلك اليوم ، ويعتد به من شهر رمضان . . . الحديث
From Abu Abdillah (s.a) it was asked about a man who goes out of his house and wants to travel while fasting, he said: “If he goes out before the half of noon he breaks and makes up for the day after and if he goes out after noon he completes it on his day.” [Tadhib Al-Ahkam, Volume 4, Page 228]
عن أبي عبد الله (عليه السلام) أنه سئل عن الرجل يخرج من بيته يريد السفر وهو صائم، قال: فقال: إن خرج من قبل أن ينتصف النهار فليفطر وليقض ذلك اليوم وإن خرج بعد الزوال فليتم يومه
(This is the comment of At-Tusi)
Shaykh At-Tusi writes: “If one goes out before noon, one is obliged to break, but if one intends to travel at night, and if he goes out after noon, he is advised to fast, but even if he breaks, he has no obligation, but if he does not intend to travel at night, he is not allowed to break, not at all.” [Tadhib Al-Ahkam, Volume 4, Page 229]