1. They are called Red-Letter Days because in calendars they were marked in red ink.
吉利日之所以叫做“红色字母日”，是因为这些日子在日历中被印成红色的缘故。
2. In the medieval calendar there were two kinds of day - Dismal Days and Red-Letter Days.
在中世纪的日历中，有两种日子&不吉利日和吉利日。
red-letter days
3. These were my red-letter days.
那些是我值得回忆的日子。
4. Dismal Days were considered unlucky, while Red-Letter Days were the principal feasts and saints'days to be celebrated or observed throughout the Christian year.
不吉利日被认为是倒霉的日子，而吉利日在基督教全年度里是重要的节日和纪念圣徒的日子。
5. Degree: Technical Secondary School or higher and major in Electronics or Machine speciality. In the medieval calendar there were two kinds of day - Dismal Days and Red-Letter Days.
学历：电子、机械类专业中专以上学历。在中世纪的日历中，有两种日子&不吉利日和吉利日。
6. E. g: it was one of the red-letter days of my life.
这是我一生中最值得纪念的日子之一。