OH YES, this is a major issue and totally blows. I've gotten calls at 2:00AM-4:00AM CST from corporate in Ireland, because to them it's in the morning. I need to reboot a production server; and am told it needs to be during off hours. BUT, we have teams in China, Japan, India, UAE (who's weekends are Friday / Saturday and are at work Sunday), Ireland, Germany, Brazil, etc. So there really isn't much of a "no use" timeslot, someone is ALWAYS using a esxi host as they have multiple servers on them...if I send out a notification I get a ton of responses "we use this server at this time" and everyone conflicts. So, now I just wait until Saturday night, take stuff down, and don't even bother to tell anyone. Last time only two people even noticed.