What happens when a Multiple 'loses time'?
Time loss happens when any resident is in Front and information is not shared to the other people in the system. In effect, those "in the back" black out and what has happened with the body is not accessible to the others.
This can be uncomfortable or distressing, if one "comes to" in a strange location, or if people report that you have done something you have no recollection of doing.
Lesser versions of time loss can also occur — a type of "losing track of time". For example, a brown out instead of a black out where you fog out and sit unmoving for a while, lost someplace else. Like even the person in front has dissociated and no one has taken over.
Other time loss includes not realizing what day of the week it is, "losing a day" you can no longer remember (even if you gain memory of it with reminders, it can be disconcerting when you honestly have no recall of yesterday even though you didn't black out and wake up in a new place).
It is possible to be functional as a multiple even if you lose time; if you know this is a concern for your system, it becomes very important to leave notes, for example. A good number of multiples never lose time at all, or only in an ordinary way (just like someone absorbed in study doesn't realize how "quickly" the time flew by). But having regular, serious long-term blackouts can be harmful to the system as a whole, and it's important to develop a protocol, track appointments, and work on agreements in the system even if it requires communication by notes, diary, emails, instant message, texts, or whatever means your system can find to communicate with each other.
Thus, it becomes important to establish and enforce "house rules", to develop co-awareness if possible, and to work toward a high level of trust and knowledge of the people in the system.