There are a number of timestamp fields visible in your Flywheel project. This article explains how Flywheel generates the session, acquisition, created, and modified timestamps.
The two images below show where you can find these timestamps in your project.
Session label (This appears as a timestamp if the session label isn’t explicitly set)
1. Session timestamp
The goal of this timestamp is to understand when data was acquired. For DICOM files, the session timestamp is generated by the DICOM classifier gear. The classifier uses the StudyDate and StudyTime tags to generate the timestamp. If those tags are not present, Flywheel will use the earliest SeriesDate and SeriesTime. Non-DICOM data can also have a session timestamp if the Connector is configured to use a known useful timestamp for that type of data. Contact your site admin for more information about your site’s configuration.
Timestamps are stored in Flywheel with a UTC +0 offset. Add a timezone to the session to determine the local time when data was captured. This is useful when time of day is important for the study, e.g. morning CT scan vs afternoon scan.
- Select the Session tab
- Choose a new date and time
- Select a timezone if necessary.
2. Acquisition timestamp
For DICOM files, Flywheel uses the AcquisitionDate and AcquisitionTime tags to generate this field. SeriesDate and SeriesTime are used if the data originated from a Siemens’ imaging machine. If none of those tags can be read by Flywheel, then the session timestamp is used.
3. Created Date timestamp
The Created Date shows when the file was uploaded to Flywheel. You cannot edit these timestamps.
4. Session label
If you do not set the session label on import, Flywheel will use the StudyDate and StudyTime tags to generate the label.
- Click the Session tab
- Enter a new label
- Click Save
Created At and Modified At
All files, jobs, and Gears include the Created At and Modified At fields in the Information section.
- Created At: when the file was uploaded to Flywheel or created within Flywheel.
- Modified At: This is updated anytime a change is made to the file. For example, it's updated when you move the file to a different subject, edit the file’s metadata, or run a gear against the file. If the action results in a new file version, the modified at timestamp becomes the created date for that file version
To view any file’s Created At or Modified At fields, select the options menu next to the file, and choose Information.
Additional timestamps considerations
- All times are represented in your computer or browser's local time, unless accompanied by an offset (e.g. +300) or time zone (e.g. CDT).
- De-identification may alter timestamps. Flywheel’s de-id profiles allow you to offset date and times when uploading your data. Contact your site admin if you do not know if your site, project, or group is using a de-id profile.
- All times visible in your project are shown in your computer or browser's local time unless accompanied by an offset (e.g. +300) or time zone (e.g. CDT).