Dates and Times in P5

All dates and times in PTAGIS are reported in Pacific Standard Time (PST). However, P5 allows times to be collected in the time zone in which you are located, by using a date time offset format.

An example of how the date time offset values are stored is below:

 

          2016-09-20T17:00:00-07:00

 

The date is in YYYY-MM-DD format and is separated from the time by the letter T. The time is in 24 hour format and is followed by the time zone offset value. Here the offset is -07:00, which indicates that it is 7 hours behind Coordinated Universal Time (UTC), and was collected in either Pacific Daylight Time or Mountain Standard Time.

 

Time zone offset values in the Columbia Basin region are:

 

 

 

All timestamps entered and displayed within P5 use this date time offset structure to promote more accurate reporting of when a certain event occurred regardless of where it was recorded. A user in the field can simply enter the local date and time into P5 and not have to think about the local time zone or if Daylight Savings is in effect. Timestamps can be automatically input during data entry with the local system time if enabled in the Repeating Values feature. Regardless, these local timestamps will eventually be converted to Pacific Standard Time (PST) when P5 data is submitted to PTAGIS as is standard for reporting.

 

The convenience of using the date time offset to store local timestamps can present some complications because P5 displays them relative to the current system time zone settings which may be different from when the data was first collected. For example, a field user in an eastern county within Idaho enters an Event Date for a mark record with a local timestamp of 2016-11-01T13:00:00-06:00 which represents Mountain Daylight Time (MDT). P5 displays the local time of this event as 11/01/2016 13:00:00. Viewing this Event Date a month later when the same system is now operating under Mountain Standard Time (MST) P5 will display it as 11/01/2016 12:00:00. This relative time shift is also observed when exporting and importing sessions between different P5 instances running on computers operating under different time zones. The original timestamps are preserved using the date time offset structure but appear to be different local times when viewed simultaneously on two computers operating under different time zones.

 

The Record Management feature allows users to optionally display event/release dates standardized to PST if the local time is not desired. The Query feature standardizes and displays all dates as PST to allow filtering of these values across sessions that have timestamps collected under different time zones. The column header indicates where a date/time value is displayed in local or PST as shown below:

 

 

NOTE: it is recognized that not all research can or needs to capture and report timestamps accurate to the hour, minute or second. In this case, enter a time value of 12:00:00 (noon) and not 00:00:00 (midnight) to prevent time zone adjustments from impacting the correct date value.