Hello Dmitry, Andrei, Quoting the draft time_namespaces manual page: Associated with each time namespace are offsets, expressed with respect to the initial time namespace, that define the values of the monotonic and boot-time clocks in that namespace. These off‐ sets are exposed via the file /proc/PID/timens_offsets. Within this file, the offsets are expressed as lines consisting of three space-delimited fields: <clock-id> <offset-secs> <offset-nanosecs> The clock-id identifies the clock whose offsets are being shown. This field is either 1, for CLOCK_MONOTONIC, or 7, for CLOCK_BOOT‐ TIME. What was the reason for exposing numeric clock IDs in the timens_offsets file? In API terms, that seems a little ugly. I think it would have been much nicer if the clocks were defined symbolically in this file. I.e., that reading the file would have shown something like monotonic x y boottime x y And that records similarly with symbolic clock names could have been written to the file. Was there a reason not to do this? Thanks, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/