To find the manufacturing date of your Samsung Galaxy phone, check the serial number. The first letter represents the year (A for 2010, B for 2011, etc.), and the second letter represents the month (A for January, B for February, etc.). For example, if your serial number starts with "CJ," it indicates your phone was manufactured in March 2018.

Actually, there are various ways to find out when your device was made, including decoding the serial or IMEI number or keying a special code on the dialer. But the easiest way I found is by using the Device Info app by Yasiru.

You can download the Device Info app by Yasiru from Google Play.

Then, open it and go to the Device tab. Here, you can see the Manufactured date field.

My Galaxy Z Flip5 was made in August 2023.