The times displayed in TargetLynx and the MassLynx security log are corrected for Daylight Saving - WKB24842

SYMPTOMS

A user notes that the times displayed in the TargetLynx audit trail are one hour later than the times that were previously displayed for the same events before the clocks changed for Daylight Saving Time. The user believes this is a compliance issue, because the recorded times of events are not permanent.

ENVIRONMENT

MassLynx 4.1 and TargetLynx, all SCNs, with or without MassLynx security.

CAUSE

In the headers of TargetLynx reports, in the TargetLynx internal audit trail, and in the MassLynx Security system audit trail, displayed times are corrected for local daylight saving time (in the UK, this is called "British summertime"). The computer stores times as UTC. As a result, when the clocks change by one hour in the spring and then again in the autumn, users may notice that the times of existing events are shifted forwards or backwards by one hour. The attached file shows the TargetLynx audit trail before and after the clocks changed in the autumn.

In the headers of TargetLynx reports, both the Last Altered time and the Signature time are affected. The signature time is used only in MassLynx security, and only when electronic signatures are used. In both cases, the current time zone is displayed (e.g., GMT), followed by either "Standard Time" or "Daylight Time".

In the system audit trail in MassLynx security, the time zone details are displayed in the Event Details window for each event in the log.

FIX or WORKAROUND

This is normal behavior; the software is working as intended. The times stored by the computer are permanent, whereas the displayed times take into account the local time zone and daylight-saving status.

This feature allows TargetLynx results files to be moved around between time zones. The results always display in the local time zone.

ADDITIONAL INFORMATION

In MassLynx, the following times are not corrected for daylight saving:

• The acquisition time for a data file. This can be displayed in the TargetLynx Summary table, in the Experimental record, and in the Chromatogram data browser.
• The Method time that is displayed near the top of the first page of every TargetLynx report. This is the time that the method file was last written to disk, and is stored in the Operating system.
• The Calibration time that is displayed near the top of the first page of every TargetLynx report. This is the time at which the calibration curves were generated in TargetLynx.