Hi kongchichen00793frzt, welcome to Thunkable! 
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This can be a bit tricky as you’re dealing with time but you’ve got the psuedo code pretty correct. You’ll want to use the comparison blocks and an if/else statement to check if the current time falls within the range of times. If the current time value is greater than the start time but less than the end time, you’ll set a label to Available, else you can set it to Unavailable.