Weekend lag is a condition affecting the body’s circadian clock, similar to jet lag, but instead stemming from altering one’s sleep hours over a weekend of hard partying and drinking rather than from a long flight.

周末时差是跟飞机时差类似的情况，通常会对人体的生物钟产生影响。只不过，导致周末时差的原因是周末聚会、豪饮以及作息时间的变化，而飞机时差主要是因为长途飞行引起的。

For example:

Monday morning classes are so rough. It’s only 8 in the morning but I feel like it is 7 PM. That’s a serious case of weekend lag.

周一早上的课真痛苦啊。虽然现在是早上8点，可我觉得好像已经是晚上7点了。严重的周末时差反应啊。