Last activity recorded on Invalid Date

Hi @bdm,
As a Mac user, I get the same error on Safari. The error appears both on English and Turkish interfaces in Safari. On Windows 10, while Microsoft Edge displays the dates without any problem, IE11 is also problematic.
When it comes to Firefox or Chrome, the dates appear in different formats.
Turkish interface: dd/mm/yyyy
English interface: m/d/yyyy or mm/dd/yyyy

My config.inc.php time format is;

; Site time zone
; Please refer to lib/pkp/registry/timeZones.xml for a full list of supported
; time zones.
; I.e.:
;
; time_zone=“Amsterdam”
time_zone = “Istanbul”

; Short and long date formats
date_format_trunc = “%m-%d”
date_format_short = “%Y-%m-%d”
date_format_long = “%B %e, %Y”
datetime_format_short = “%Y-%m-%d %I:%M %p”
datetime_format_long = “%B %e, %Y - %I:%M %p”
time_format = “%I:%M %p”

Some screenshots are attached.
Regards,

safari_eng

firefox_eng

firefox_tr