it's difficult to be prepared for which version of your partner will come home; the smiley, happy (normal) person who had a good day or that miserable '"I hate my life" twin who comes home under a cloud. This can be determined based on the time that they finish work; if the business closes at midnight and there are members of the public saying "well it's on 11.45pm, we have plenty of time" this can cause automatic anger, especially when you work in a bar or a restaurant. Staff have homes to go to, people.