The deprecated DateTime data type has the tag value -15. The suggested alternative is the Timestamp data type, which has tag value -12. In both cases, the following documentation page states that the size is 8 bytes.
https://code.kx.com/q/basics/datatypes/
However, on this documentation page
Data types | Basics | kdb+ and q documentation - kdb+ and q documentation
the following is stated:
The 4-byte datetime datatype (15) is deprecated in favour of the 8-byte timestamp datatype (12).
Internally, dates, times and timestamps are represented by integers:
This suggests that the deprecated DateTime datatype is a 4 byte integer.
On another documentation page
2. Basic Data Types – Atoms - Q for Mortals
the following is written.
A datetime value stores in a float the fractional day count from midnight Jan 1, 2000.
Combining this with the above, it is unclear as to whether the deprecated Datetime (-15) type is a 4 byte or 8 byte floating point value.
Is anyone able to clarify?