Time zero depends on the tracks loaded¶

A file's time zero is its first record of any track. Loading only some tracks moves the zero to their first record: seconds later, and up to hours.


Status	established: shown on many cases, with a control.
Devices	Vital Recorder

What it means¶

Times "from the start" taken from different track subsets are not on one axis. The arrhythmia database's annotations count from the full file's zero.

The TimeNet import reads whole files and keeps the full-file zero (vital_origin_s).

Parameter	Value	Status	From
SNUADC start after the file's first record	1.56 s (5–95%: 0.44–4.5 s; 99th percentile 12 s; maximum 10,879 s)	measured	The vitaldb package's loading conventions

Study	Date	Status	Summary
The vitaldb package's loading conventions	2026-10-17	current	The vitaldb Python package sets time zero from the tracks loaded, places waveform blocks by rounding their stamps up to a sample, and lets overlapping blocks overwrite each other. Each choice moves or loses samples.
Time zeros and loaded subsets	2026-10-16	current	A VitalDB time "from the start" depends on which tracks were loaded: loading a subset moves the zero to that subset's first record, seconds or hours later. The arrhythmia database's annotations count from the full file's zero.