Silsilah as-Sahihah 839 — Not fasting just before Ramadan, except

It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that the Noble Prophet (peace and blessings be upon him) said: "Fast upon sighting the moon and break your fast upon sighting the moon. If clouds, darkness, or dust come between you and the moon, then complete the counting (of thirty days) of Sha'ban. Do not anticipate the month, nor join Ramadan with a day from Sha'ban."