This procedure is defined in the server but not documented via ad_proc or proc_doc and may be intended as a private interface.
The procedure is defined as:
proc tdav::lock_timeout_left {timeout locktime} {
set locktime [clock scan $locktime]
set lockexpiretime [clock scan "$timeout seconds" -base $locktime]
set timeout_left [expr {$lockexpiretime - [clock seconds]}]
if {$timeout_left < 0} {
set timeout_left 0
}
return $timeout_left
}