How Time Is Represented in a Source
Explore the ways that Visier defines time for records uploaded to our platform.
The following table defines key terms related to time in data uploads.
| Term | Definition |
|---|---|
| Timestamp | A time value added by a program or system to a file, message, or record indicating the time and date when the file, message, or record was created or last modified. |
| Time shifting | Modifying a timestamp via edit, script, or calculation. |
| Upload time | A timestamp for when a record was uploaded to the platform. |
| Snapshot time | A timestamp representing when a record was true in the source system. |
Snapshot time
The snapshot time represents when a record was true in the source system, such as an HRIS, and is typically the moment of export. By default, Visier overwrites the original snapshot time with the Upload time (UTC) when the file is uploaded to the platform.
Example:
- If you exported a set of records from your HRIS on 2020 August 1 at 09:00:13.214Z. The time of the export is the snapshot time. If you upload these records to Visier on 2020 August 5 at 3:00PM, that is the upload time (UTC). Because the UTC overwrites the original snapshot time, there is a time difference of about four days and six hours later. You can adjust the snapshot time by minus 102 hours to represent the original snapshot time.
- If you uploaded a file three months ago and want to replace a record in that file by uploading a new file today, you can change the snapshot time of today's file to three months ago to correct the previously uploaded records.
Use the following optional parameters to adjust the snapshot time so it accurately reflects when the data was exported:
- Offset (hours): An integer value used to shift the time. The platform calculates the time as: Snapshot time = Upload time + Offset
- Snap to midnight: When enabled, the snapshot time moves to the start of the day. This zeros the time portion of the timestamp, for example, 20200801 09:00:13.214Z becomes 20200801 00:00:00.000Z.
These settings can be configured in source settings. For more information, see Source Settings.
Visier's time zone adjustment
By default, Visier stores all date data in UTC. If your data is stored in a different time zone format, you can adjust it using the following methods:
- Change the time zone when loading your source data using a Visier Extraction Rule. For example, using the shiftHours rule shiftHours(dateColumn(timeStamp), 5) would adjust the value of the date column, in this case timeStamp, by 5 hours. Note that all changes to the time zone are done relative to UTC. For more information, see shiftHours.
- Specify the time zone by including time zone data directly in the record. The new time will be explicitly stated in the source data using the format yyyy-MM-dd HH:mm:ss.SSS z, with the z value stipulating the abbreviated new time zone. For example, 2025-07-15 21:32:12.023 PST.