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Slot: Time Column (time_column)

Name of the column carrying the observation date / timestamp (e.g. date).

Tier: recommended

Why this slot matters

Without knowing which column carries the date or timestamp, each value cannot be placed in time, so exposure values cannot be aligned with clinical events — which day's exposure goes with which health record — and any lag or window analysis is impossible.

In plain terms

This names the column that gives each measurement its "when" — a date column for daily data, or a year column for annual summaries.

URI: envar:slot/time_column

Applicable Classes

Name Description Modifies Slot
DataLayout How the companion data file (CSV / parquet) is laid out and how this record's... no

Properties

Type and Range

Property Value
Range String
Domain Of DataLayout

Cardinality and Requirements

Property Value

Examples

Value
date
year

Identifier and Mapping Information

Annotations

property value
tier recommended
justification Without knowing which column carries the date or timestamp, each value cannot be placed in time, so exposure values cannot be aligned with clinical events — which day's exposure goes with which health record — and any lag or window analysis is impossible.
explanation This names the column that gives each measurement its "when" — a date column for daily data, or a year column for annual summaries.
covered_by None

Schema Source

Mappings

Mapping Type Mapped Value
self envar:time_column
native envar:time_column

LinkML Source

name: time_column
annotations:
  tier:
    tag: tier
    value: recommended
  justification:
    tag: justification
    value: Without knowing which column carries the date or timestamp, each value
      cannot be placed in time, so exposure values cannot be aligned with clinical
      events — which day's exposure goes with which health record — and any lag or
      window analysis is impossible.
  explanation:
    tag: explanation
    value: This names the column that gives each measurement its "when" — a `date`
      column for daily data, or a `year` column for annual summaries.
  covered_by:
    tag: covered_by
    annotations:
      omop_gaia:
        tag: omop_gaia
        annotations:
          extent:
            tag: extent
            value: partial
          status:
            tag: status
            value: asserted
          where:
            tag: where
            value: external_exposure attr_start_date / attr_end_date (window-wide,
              not per-day)
          note:
            tag: note
            value: 'GAIA carries date columns but collapses every row to the variable''s
              window-wide attr_start_date/attr_end_date — per-day external_exposure
              does not come out. Conservative: partial.'
      degauss:
        tag: degauss
        annotations:
          extent:
            tag: extent
            value: full
          status:
            tag: status
            value: verified
          where:
            tag: where
            value: one row per (person × day) in cohort_addresses_geocoded_daymet
              CSV (per-day date)
          evidence:
            tag: evidence
            value: EnVar/examples/heat/COMPARISON.md §D (One row per person × day
              — ✅ for DeGAUSS)
          note:
            tag: note
            value: DeGAUSS emits a per-day date on every row (24 rows, per-day).
      amadeus:
        tag: amadeus
        annotations:
          extent:
            tag: extent
            value: full
          status:
            tag: status
            value: verified
          where:
            tag: where
            value: one row per (person × day) in gridmet_tmmx.csv (per-day date)
          evidence:
            tag: evidence
            value: EnVar/examples/heat/COMPARISON.md §D (One row per person × day
              — ✅ for Amadeus)
          note:
            tag: note
            value: Amadeus emits a per-day date on every row (24 rows, per-day).
      cher:
        tag: cher
        annotations:
          extent:
            tag: extent
            value: partial
          status:
            tag: status
            value: asserted
          where:
            tag: where
            value: table_column_dictionary column tagged Temporal – Primary
          note:
            tag: note
            value: 'C-HER tags time columns first-class via the Temporal – Primary
              tag, but not as a portable sidecar time binding. Conservative: partial.'
      codata:
        tag: codata
        annotations:
          extent:
            tag: extent
            value: out_of_layer
          status:
            tag: status
            value: asserted
          where:
            tag: where
            value: no column
          note:
            tag: note
            value: The time-column binding is instance-layer layout, outside CODATA's
              conceptual scope.
description: Name of the column carrying the observation date / timestamp (e.g. `date`).
title: Time Column
examples:
- value: date
  description: daily data
- value: year
  description: annual aggregate
from_schema: https://w3id.org/linkml/microschemas/envar
rank: 1000
domain_of:
- DataLayout
range: string