I created a spreadsheet on Google Docs:
https://docs.google.com/spreadsheets/d/1NMg1HhuQw8irg2eiQdzxdQGNcK60ljNWM4HZMvV-vXg/edit?usp=sharing
Enter your nickname separated by commas in the each cells with a convenient hours for you.
Be careful when entering data. If you accidentally deleted information in a cell, use the CTRL+Z command to correct the error.
Thanks!