How to write build time stamp into apk

Question

1. Making some changes in Android Contacts package
2. Using mm (make) command to build this application

Because I have to change and

Answer 1

Edit: My answer does not work anymore since option keepTimestampsInApk was removed. Working in 2020 is https://stackoverflow.com/a/26372474/6937282 (also https://stackoverflow.com/a/22649533/6937282 for more details)

Original answer:

A hint for solution "last modification time of classes.dex file" an newer AndroidStudio versions: In default config the timestamp is not written anymore to files in apk file. Timestamp is always "Nov 30 1979".

You can change this behavior by adding this line to file

%userdir%/.gradle/gradle.properties (create if not existing)

android.keepTimestampsInApk = true

See Issue 220039

(Must be in userdir, gradle.properties in project build dir seems not to work)