You can use the in-built iPad app to do this, but it's not obvious how.
Say your colleague is on vacation from Today (Sunday) until, say, Friday. OK, start a new entry into the calendar on the start day. It gives you the option of the start time and the end time. By default the end time shows that the event only lasts that one day. i.e it finishes some time on Sunday.
But go into the end time and notice that you can not only scroll the end *time* but also the end *day* and you can scroll ahead as far as you want.
That's the good news. You'll find that your colleague's vacation will show in the Day and Week view correctly but, for some reason, the Month view (which I use the most) only shows the start of the vacation and not the fact that it's active on every day after today until Friday.
Maybe someone out there knows how to get it to display correctly in the Month view, but I can't figure it out. So, maybe this is the answer to your question but if, like me, you mostly use the Month view, it may not be satisfactory.
Tim
Scotland