hour — Extract hour numbers from datetime values.
hour extracts the hour component from a datetime scalar or array and returns the result as doubles with the same shape as the input.
How hour works
hour(t)accepts datetime scalars and datetime arrays.- The output shape matches the input shape.
- Hour values are returned in 24-hour clock form.
- Passing a non-datetime value raises a datetime-specific error.
How RunMat runs hour on the GPU
hour does not dispatch GPU kernels; it extracts the hour component from CPU-side datetime objects.
GPU memory and residency
No. hour reads datetime objects on the CPU and returns ordinary host-side numeric arrays.
Examples
Extract the hour from a scalar datetime
t = datetime(2024, 4, 9, 13, 30, 5);
h = hour(t)Expected output:
h = 13Extract hours from a datetime array
t = datetime([2024 2024], [4 4], [9 9], [8 17], [15 45], [0 0]);
h = hour(t)Expected output:
h =
8 17FAQ
What clock convention does hour use?⌄
It returns 24-hour clock values such as 0, 13, or 23.
Does hour preserve the input shape?⌄
Yes. The numeric output has the same size as the input datetime array.
Does hour run on the GPU?⌄
No. datetime values are host-side objects, so hour executes on the CPU.
Related Datetime functions
Open-source implementation
Unlike proprietary runtimes, every RunMat function is open-source. Read exactly how hour works, line by line, in Rust.
- View hour.rs on GitHub
- Learn how the runtime works
- Found a bug? Open an issue with a minimal reproduction.
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