Which software, provides simple editing for a timetable chart with dynamic text?

I'm looking for a simplified spreadsheet, which is more focused on creating a graphical timetable, that I can can create boxes on, and within the boxes, add text in different sizes and format. Something I could do by drawing, and using overlays; but then digitial for e.g. a weekly schedule, and which could more easily re-size and edit text in boxes. That's all, no more no less, end result would be a PDF or PNG/JPG.