second — Extract second components from datetime values with MATLAB-compatible output shapes.
second extracts the seconds component from datetime scalars or arrays and returns doubles with the same shape as the input. Fractional seconds are preserved when sub-second precision exists.
Syntax
X = second(t)Inputs
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
value | Any | Yes | — | Datetime input. |
Returns
| Name | Type | Description |
|---|---|---|
X | Any | Numeric scalar/tensor result. |
Errors
| Identifier | When | Message |
|---|---|---|
RunMat:datetime:InvalidArgument | Arguments or option grammar do not match supported datetime forms. | datetime: invalid argument |
RunMat:datetime:InvalidInput | Input values cannot be parsed/converted/broadcast to a valid datetime result. | datetime: invalid input |
RunMat:datetime:Internal | Internal datetime state or indexing/evaluation failed unexpectedly. | datetime: internal operation failed |
How second works
second(t)accepts datetime scalars and datetime arrays.- The output shape matches the input shape.
- Returned values are doubles so fractional seconds can be represented.
- Passing a non-datetime value raises a datetime-specific error.
Does RunMat run second on the GPU?
second does not dispatch GPU kernels; it extracts the second component from CPU-side datetime objects.
GPU memory and residency
No. second reads datetime objects on the CPU and returns ordinary host-side numeric arrays.
Examples
Extract whole seconds from a scalar datetime
t = datetime(2024, 4, 9, 13, 30, 5);
s = second(t)Expected output:
s = 5Preserve fractional seconds
t = datetime(2024, 4, 9, 13, 30, 5.25);
s = second(t)Expected output:
s = 5.2500Using second with coding agents
Open a RunMat example with live inputs, then ask the agent to explain how second changes the result.
Run a small second example, explain the result, then change one input and compare the output.
FAQ
Can second return fractional values?⌄
Yes. RunMat preserves fractional seconds and returns them as doubles.
Does second preserve the input shape?⌄
Yes. The numeric output has the same size as the input datetime array.
Does second run on the GPU?⌄
No. datetime values are host-side objects, so second executes on the CPU.
Related Datetime functions
Open-source implementation
Unlike proprietary runtimes, every RunMat function is open-source. Read exactly how second is executed, line by line, in Rust.
- View the source for second in Rust on GitHub
- Learn how the RunMat runtime works
- Found a bug? Open an issue with a minimal reproduction.
About RunMat
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