Now that you have started the school year and work for most, it is best to schedule the tasks on a calendar like that just I've prepared in Excel 2007.
When I'm designing Excel calendars, I always use the date format in cells to gain an advantage in handling of it (conversion to the days of the week, the names of the months of the year, transactions with dates, automatic translation, etc.), as shown in the following video which, although done with Excel 2010, can serve as an explanation for earlier versions, although many do not support all these conditional formatting:
This calendar can be translated into several languages, writing texts in the "Idiomas" sheet and searching them using the following formula:
being defined in the Name Manager:
Langs =Idiomas!$1:$1 (different languages in row 1)
Trans =Idiomas!$A:$Z (translations of each language in columns A to Z)
For example, to:
Idiomas!$A$19 = New Year (English)
It is translated by:
Idiomas!$B$19 = Año Nuevo (Spanish)
The language is chosen from the dropdown of the cell R2 in the "Cal" sheet: English or Español.
You can include more languages on the page "Idiomas" in columns C and following.
The hardest part has been Find the numbers of tasks into overlapped date ranges, but with the help of AyudaExcel forum members, I could fix it with this formula and without auxiliary cells, always searching only a limited number of overlapping tasks (solved for 4 task numbers):
Formula confirmed with Ctrl+Shift+Enter
I've scheduled in the calendar the holidays in Zaragoza and the United States, and such as tasks, the Fiestas del Pilar and you can add or delete feasts and tasks individually in the "Fechas" and "Tareas" sheets, respectively.
Update 03/12/2013: PW2 version of this calendar shows in the month sheet two events or anniversariesfor the same day, marking the day with the color of the first event. The PW3 version shows until 5 events per day with the auxiliary columns G:K in the Dates sheet.
Update 09/19/2013: PW4 version shows task names in the "Mes" sheet.