TIP 423: Formatting Timestamps with Milliseconds

Author:		Thomas Perschak <[email protected]>
State:		Draft
Type:		Project
Tcl-Version:	9.1
Vote:		Pending
Created:	07-Jun-2013
Keywords:	Tcl, time, millisecond resolution


This TIP describes a change to clock format to allow it to handle timestamps with sub-second accuracy.


Currently, the clock format accepts only integer numbers for clock formatting. Since the clock milliseconds command was introduced in Tcl 8.5, this limitation seems a bit restrictive.

In particular, the timestamp column in a number of databases (e.g., http://www.postgresql.org/docs/9.1/static/datatype-datetime.html\) handles high-resolution timestamps by allowing full ISO 8601 times, which look like "04:05:06.789"; this would simplify database write operations.


The clock format command should accept floating point values for timestamps.

Another format letter should be added to clock format which puts the milliseconds into the output string; the millisecond value should not be written unless explicitly requested.


This document has been placed in the public domain.