TIME

ASN.1 defines several universal types for representing time and date information: TIME, DATE, TIME-OF-DAY, DATE-TIME, and DURATION.

While each has a distinct semantic meaning, their underlying ASN.1 encoding is based on strings, and they are not natively implemented in the library. This means that users must define them manually in their ASN.1 module before use.

A typical set of ASN.1 definitions for these types might be:

TIME ::= [UNIVERSAL 14] VisibleString
DATE ::= [UNIVERSAL 31] IMPLICIT TIME
TIME-OF-DAY ::= [UNIVERSAL 32] IMPLICIT TIME
DATE-TIME ::= [UNIVERSAL 33] IMPLICIT TIME
DURATION ::= [UNIVERSAL 34] IMPLICIT TIME

The above definitions map the time-related types to a VisibleString base type (or to TIME in the case of derived types). This allows them to be handled as textual data while still using the correct ASN.1 universal tags.

Python Representation

Since these types are defined as string-based in ASN.1, their generated Python classes will wrap a native str value.

Example generated Python classes might look like:

class TIME(_Asn1BasicType[str]):
    pass

class DATE(_Asn1BasicType[str]):
    pass

class TIME_OF_DAY(_Asn1BasicType[str]):
    pass

class DATE_TIME(_Asn1BasicType[str]):
    pass

class DURATION(_Asn1BasicType[str]):
    pass

Conceptual Representation

All of these types follow the same general pattern:

class _Asn1BasicType[str]

Represents an ASN.1 string-based time type.

__init__(self, value: str | None = None) → None

Initializes the instance with an optional string value.

property value: str

Gets or sets the string value.

The value should conform to the expected format for the specific time type (e.g., ISO 8601 format for DATE-TIME), but no automatic format validation is performed unless implemented by the user.