If "how long can you go before you absolutely have to wash your hair or you will have no friends" was an Olympic sport, I would rock at it.
Sadly, I don't think that would fit across the news marquee, so whatever.
This is a hair idea for days when 15 more minutes of sleep wins over shampooing:
These were taken JUST NOW in the English department lounge, thus the studious bookshelf background.
Take any headband (I like Pink Pewter because they're fabric-backed and won't slip. Plus, sparkles), and put it on like you're going to wear it hippie-style. Then tuck all your hair up in the back. Styles like this make me thankful that "messy hair" is a thing right now, because it's pretty much impossible to do it perfectly.
Two minutes and you're out the door!