The older AppKit API supports seconds in its Date Picker, but they’ve been dropped from its SwiftUI successor. There are many other signs our Macs are moving to less precise time. Is this intentional, to reverse our slavery to time?
Mach absolute time
Apparently based on Mach absolute time, log entry times are converted to wallclock times. This exposes them to the vagaries of time zones, seasonal adjustments, and periodic wallclock adjustments. Here’s how all that works, and can confuse.
It turns out that ‘nanosecond’ times introduced in LogUI are largely artefact. Is higher resolution timing really needed, and how can it be obtained?
Two basic rules: M1 Macs run Arm-native code when it’s available, but won’t mix ARM-native and Intel code in the same process. Here are the details.
Time has changed in M1 Macs, with the Mach clock ticking every 41.67 nanoseconds. This affects all log entries too, and works differently in Rosetta.
New version of Mints tells you the scaling factors required to convert raw Mach absolute time values to nanoseconds, which change on Apple Silicon Macs.
The more you look at changes to Mach Absolute Time coming in Apple Silicon Macs, the more messy they become, largely because the docs are so incomplete.
Since we switched to Intel Macs, Mach precision time has ticked away in nanoseconds. That’s won’t be true in Apple Silicon Macs, and could have strange results.
Picking the right time system for the purpose is critical when you want to analyse very short periods. Sometimes it takes time to discover how to juggle with time.
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