What if the clock of the FMS13 or the mobile device is not accurate?

[dickiechung]

If a user of a mobile device set the clock of his device wrongly, say year 2015 becomes 2014, and do a sync with EasySync, would it mess up data in the FMS13 server? If so, what would be the best strategy to avoid such incidence. In general, how can we synchronize the clock of the server and the mobile devices BEFORE a sync action is done by EasySync?

[timdietrich]

To avoid these types of issues, EasySync uses UTC timestamps to keep track of all date/time-related information that is needed to coordinate syncing. This also allows us to sync data with users in different timezones.

 

- Tim

[dickiechung]

Hi Tim,

 

Thank you for your feedback. I am afraid UTC Timestamp does not fully solve the problem. I tested the Get ( CurrentTimeUTCMilliseconds ) of Filemaker. If I change the system clock, the value return by Get ( CurrentTimeUTCMilliseconds ) will change accordingly. The Help of Filemaker does not mention that Get ( CurrentTimeUTCMilliseconds ) needs an internet connection for an external reference of the precise UTC Time.

 

What I worry is when a mobile device is used offline, the modified time will be set according to the system clock. Another scenario: what happen when 2 databases are synchronised over an intranet with with no internet connection to get the precise UTC time? Will they both rely on their own system clock to get the UTC time?

 

My preliminary test of EasySync seems to indicate that the accuracy of the system clock do matter.

[bcooney]

Running into this now. 

[comment]

What are your expectations?

[bcooney]

I think now that I've thought this through,  Get ( CurrentTimeUTCMilliseconds ) calcs UTC from the system's local time and time zone. So, as long as the workstation's time and time zone are accurate, the function will return an accurate value.