Availability Scheme in database

I'm currently designing a website which can help my rowing team plan training times and such. The basic idea is that every rower can set the times they can train. Coaches can then see the availability of all the rowers in a handy table and can use this to plan a training.

My question is, how should I represent availab开发者_运维问答ility in the class diagram and database?

The idea that I had was to divide days into time blocks: Block 1 stands for 7:00 - 7:30, block 2 stand for 7:30 - 8:00. Then I will create a table 'timeblocks' with the following attributes:

• block_id
• user_id
• date (day, month and year)
• block_number
• availability

Is this a efficient way of storing availability data?\

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Another way you can normalization this table into two piece. a special block table and availability table.

block :

• Block_id
• block_range

Time_Block

• Time_blockId
• Block_ID
• user_ID
• Date
• Availability