1. Time flies like an arrow and days pass like a shadow.

例句：I can’t believe how quickly time flies like an arrow and days pass like a shadow since I graduated from college.

2. Time speeds by as swiftly as an arrow and as rapidly as a shadow.

例句：It seems like just yesterday we were kids, and now time speeds by as swiftly as an arrow and as rapidly as a shadow.

3. The days slip away like a shadow, and time flies like an arrow.

例句：In the blink of an eye, the years have slipped away like a shadow, and time has flown by like an arrow.

这三种翻译都很好地传达了原成语的含义，可以根据具体语境和个人喜好选择使用。