Gul posted on his Twitter his regret that he wouldn't be able to attend official celebrations because of his doctor's recommendations, Today's Zaman reported.
"Thanks to God, my health is improving. My doctors are sharing the most recent information [about my health] with you," Gul posted on his Twitter page.
Gul also said he wasn't "wasting time" in the hospital, Today's Zaman said.
"I am going ahead with my studies. I am reading reports and books," Gul said in a post that included a photo of him reading a report on clashes in Syria.
Gul was hospitalized Aug. 23, cutting short a visit to Kyrgyzstan for the Second Summit of the Cooperation Council of Turkic Speaking States in Bishkek.
Today's Zaman said Gul postponed foreign travel for two months on the recommendation of his doctor. His physician said the president was improving and was slowly returning to his daily routine.
Victory Day on Aug. 30 marks the military victory in the final battle of Turkey's Independence War in 1922.