We weigh our babies every day on the night shift (before midnight). Our babies that are in Level 3 unit (most critical care level) are not bathed or seldom bathed. When those babies are transferred in our Level 2 unit (intermediate care level), they get bathed once every other day (as assignment load permits!) and we change linens when they are bathed. For the smaller babies, they get bathed inside the incubator and we put an incontinence pad underneath them so as not to wet the whole bed. We dry them off, wrap them up and change the linens afterward.
All of our babies' incubators are changed on a weekly basis and we change the linens when we do the incubator switch.
As for our babies that are Level 1 care, they are usually bathed by their parents when they come for a visit as they are all in cribs by then.
Hope this was helpful!