set base [clock scan 20040309T020000 -gmt true]
set today [clock format $base -format %Y%m%d -gmt true]
set bad [clock scan 1600 -base $base -gmt true]
set good [clock scan ${today}T160000 -base $base -gmt true]
puts "bad: $bad [clock format $bad -format {%Y-%m-%d %H:%M:%S} -gmt true]"
puts "good: $bad [clock format $good -format {%Y-%m-%d %H:%M:%S} -gmt true]"

