From a701ae261e94257426c338a239bd16d53765a055 Mon Sep 17 00:00:00 2001 From: Stefan Appelhoff Date: Wed, 6 Oct 2021 14:58:54 +0200 Subject: [PATCH] FIX: Clarify shifting dates RECOMMENDED, add example EDF --- src/02-common-principles.md | 7 +++++-- src/03-modality-agnostic-files.md | 3 +++ 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/src/02-common-principles.md b/src/02-common-principles.md index 72323978c5..74394ecea1 100644 --- a/src/02-common-principles.md +++ b/src/02-common-principles.md @@ -734,8 +734,11 @@ Describing dates and timestamps: - Dates can be shifted by a random number of days for privacy protection reasons. - To distinguish real dates from shifted dates, always use year 1925 - or earlier when including shifted years. + To distinguish real dates from shifted dates, + is is RECOMMENDED to set shifted dates to the year 1925 or earlier. + Note that some data formats do not support arbitrary recording dates. + For example, the [EDF](https://www.edfplus.info/) + data format can only contain recording dates after 1985. For longitudinal studies dates MUST be shifted by the same number of days within each subject to maintain the interval information. For example: `1867-06-15T13:45:30` diff --git a/src/03-modality-agnostic-files.md b/src/03-modality-agnostic-files.md index d0d58e24d0..be5fd7c96f 100644 --- a/src/03-modality-agnostic-files.md +++ b/src/03-modality-agnostic-files.md @@ -431,6 +431,9 @@ This way relative timing would be preserved, but chances of identifying a person based on the date and time of their scan would be decreased. Dates that are shifted for anonymization purposes SHOULD be set to the year 1925 or earlier to clearly distinguish them from unmodified data. +Note that some data formats do not support arbitrary recording dates. +For example, the [EDF](https://www.edfplus.info/) +data format can only contain recording dates after 1985. Shifting dates is RECOMMENDED, but not required. Additional fields can include external behavioral measures relevant to the