What is the sample time of discrete blocks that inherit from a 0-sample-time continuous signal block?

Picture a simple Simulink model with a sine wave function of sample time set to 0.

This is connected to a Unit Delay block with sample time -1 (inherited).

The output of the delay block is discrete. The Timing Legend shows it in red (discrete), with a period of 0.3.

Is this period the sample time of the output of the discrete block?

How is this period of 0.3 defined/calculated?