Holidays and Absences are in different tabs in your user area but the process of request is pretty similar. 

In either tab first press

For a holiday you will be asked to complete the dates from and to, if it is half a day and then to add a note. 

For a absence you will be asked for the same information but first you will be requested to add and Absence Type and a sub type if applicable.  

Then press

Your request will be submitted and follow the approval process. 

You will be able to see the status of your request in you main view.