The computer you have appears to be one of the present production cycle;
the numbers you see are the product cycle and not the manufacture date.
Introduced: March 2015
Discontinued --
Model Identifier: MacBookPro12,1
Model Number: A1502
EMC 2835
Order Number: MF839LL/A (2.7 GHz with 128 GB storage) MF840LL/A
(2.7 GHz with 256 GB storage) MF841LL/A (2.9 GHz with 512 GB storage)
You could see the week, year and month, etc of build manufacture in some
of the online Serial Number Lookup sites. Not sure of their security. Do not
post the serial number in your posts, that would be deleted by a Host.
• Mac Serial Number Info - Lookup Your Serial Number:
https://www.powerbookmedic.com/identify-mac-serial.php
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The generally higher-spec MacBook Pro 15-inch models are set apart from 13-inch.
To compare their specs see everymac.com; or get database app from Mactracker.ca
In any event...
Good luck & happy computing! 🙂