Kitzur Shulchan Aruch, Rabbi Shlomo Ganzfried
Chapter 76 : The Laws of the Prayers on Shabbos and Yom Tov
We are accustomed to recite the chapter entitled Bameh madlikin, [on Friday evening]. It is not said when Yom Tov falls on Shabbos, nor when Yom Tov falls on Friday, and not on Shabbos Chol Hamoed.
It is customary not to arise as early on Shabbos to go to the synagogue as during weekdays, since sleep is one of the pleasures of Shabbos. This custom is supported by a Scriptural verse; concerning the daily offering on weekdays it is said: "In the morning," but concerning the Shabbos offering it is said: 'And on the Shabbos day," which indicates a later time (in the day). However you must be careful not to delay the reading of Shema and Shemoneh Esrei [beyond the proper time, see chapters 17, 18.]
The time for the Mussaf service is immediately after the Shacharis service. And it must not be delayed later than the end of the seventh hour. The person who recites Mussaf after seven hours is called a transgressor, but nevertheless his obligation is fulfilled because the time (for reciting Mussaf) is all day.