Default monitor profiles do not have a calibration date.
Richard Hughes
richard@hughsie.com
Why don’t the default monitor profiles have a calibration expiry?
The default color profile used for each monitor is generated
automatically based on the display
EDID which is stored in a memory chip inside the monitor.
The EDID only gives us a snapshot of the available colors the monitor
was capable of displaying when it was manufactured, and does not
contain much other information for color correction.
Getting a profile from the monitor vendor or creating a profile
yourself would lead to more accurate color correction.