Consider the following scenario:
You use Microsoft Lync 2013 (Microsoft Skype for Business) and have the Korean or Japanese language pack installed.
You set the Short time regional configuration option in the Korea or Japan region to the tt hh:mm format on your computer.
You set the Long time regional configuration option in the Korea or Japan region to the tt h:mm:ss format on your computer.
You send instant messages (IM) to someone in Skype for Business.
In this scenario, the times in the IM conversations display only PM or AM in Korea or Japan and do no display any number-based time value.
Note To set the Short time and Long time regional configuration options in the Korea or Japan region on a computer, go to Control Panel > Region and Language, and then, on the Formats tab, select the tt hh:mm option in the Short time format and select the tt h:mm:ss option in the Long time format.
To fix this issue, install the October 13, 2015 update (KB3085581) for Lync 2013 (Skype for Business).
Note Lync 2013 was upgraded to Skype for Business in April 2015.
To work around this issue, make one of the following changes in Control Panel:
Change the Short time format from tt hh:mm to HH:mm.
Change the region from Korea to English to change a double-byte character set (DBCS) display for time.