So [DateUtils.getRelativeTimeSpanString()][1] in the Android SDK works great for showing relative times that are in the past.
i.e: 5 days ago, or 5 minutes ago.
I'd try using DateUtils.getRelativeTimeSpanString(time, now, minResolution) as it works for future dates using an "in n days" format.
DateUtils.getRelativeTimeSpanString(time, now, minResolution)
http://developer.android.com/reference/android/text/format/DateUtils.html#getRelativeTimeSpanString