In some contexts, where both the imperfective (incomplete: present/future) and perfective (complete: past) tenses are acceptable, the perfective is considered more polite. This is only at the completion of an activity; common examples are ありがとうございました "arigatō gozaimashita" "thank you (for a completed favor)", ご馳走様でした "go-chisō-sama deshita" "it was a feast (for a completed meal)", 失礼しました "shitsurei shimashita" "I have been rude (when leaving, after a visit)". For example, when entering someone's office, one conventionally says 失礼します "shitsurei shimasu," as the visit is not complete yet, while when exiting one may say either "shitsurei shimasu" or, more politely, 失礼しました "shitsurei shimashita." Many phrases cannot be used in the perfective in this way, as the referent is as yet incomplete. For example, the standard greeting お早うございます "ohayō gozaimasu" "Good morning" (lit. "It is early") cannot be said as ×お早うございました *"ohayō gozaimashita" "It was early", as it is used only during the morning.