modification timestamp (property)

{
    "$id": "https://schemas.optimade.org/defs/v1.2/properties/optimade/files/modification_timestamp",
    "$schema": "https://schemas.optimade.org/meta/v1.2/optimade/property_definition.json",
    "title": "modification timestamp",
    "x-optimade-type": "timestamp",
    "x-optimade-definition": {
        "label": "modification_timestamp_optimade_files",
        "kind": "property",
        "version": "1.2.0",
        "format": "1.2",
        "name": "modification_timestamp"
    },
    "type": [
        "string",
        "null"
    ],
    "description": "Timestamp of the last modification of file contents. A modification is understood as an addition, change or deletion of one or more bytes, resulting in file contents different from the previous.\n\n**Requirements/Conventions:**\n\n- Timestamps of subsequent file modifications SHOULD be increasing (not earlier than previous timestamps).",
    "examples": [
        "2020-04-05T14:30:20Z"
    ],
    "x-optimade-unit": "inapplicable"
}