David T. Lewis uploaded a new version of Kernel to project The Trunk:
http://source.squeak.org/trunk/Kernel-dtl.850.mcz

==================== Summary ====================

Name: Kernel-dtl.850
Author: dtl
Time: 14 May 2014, 7:46:05.064 am
UUID: 59305e44-d447-499c-82f8-44c7d5ae25ee
Ancestors: Kernel-nice.849

Provide DateAndTme>>floor so that ObjectHistoryMark does not need to use instVarAt:put: to obtain a time stamp with whole seconds. This protects for future changes to DateAndTime that may not rely on an instance variable named #nanos.

=============== Diff against Kernel-nice.849 ===============

Item was added:
+ ----- Method: DateAndTime>>floor (in category 'squeak protocol') -----
+ floor
+ 	"Answer a copy with magnitude rounded down to the nearest whole second"
+ 	^self class basicNew
+ 		ticks: (self ticks at: 3 put: 0; yourself)
+ 		offset: offset.
+ !