Former US President George H.W. Bush will spend at least another day at a Houston hospital where he is under observation while recovering from his second bout of pneumonia in three months, his spokesman said on Wednesday.Bush, 92, was admitted to Houston Methodist Hospital on Friday for a cough that was later diagnosed as a mild case of pneumonia, family spokesman Jim McGrath said."Mr. Bush had a good night's rest, and his spirits are high," McGrath said in a statement. "Although he will not be discharged today, he is already looking forward to going home to Mrs. (Barbara) Bush who has been constantly by his side."McGrath's statement did not say when the former president was likely to be released from the hospital.In his previous encounter with the respiratory illness, Bush spent more than two weeks at Houston Methodist in January, much of it in the intensive care unit. Mrs. Bush, 91, had an overlapping stay at the same hospital for treatment of bronchitis.The couple marked their 72nd wedding anniversary on Jan. 6.Bush, the nation's oldest living ex-president, served a single term in the Oval Office as America's 41st commander-in-chief from 1989 through 1993.