A user must be online at least once after a test begins to receive new resource data from Swrve. Once this happens, they are placed in a test variant (if eligible) and the Swrve SDK uses the relevant resource attributes for that variant. Once you end an A/B test, the user must go online at least once in order to stop receiving attributes for their test variant.
On January 1st, you start a test of your menu color. The next day, a user starts your app and is placed in the variant in which the menu color is red. They then go on a 10-day vacation with no internet access. You end the test on January 7th, but they continue to see a red menu until they return on January 12th.
Typically, very few users experience extended offline periods. Only data received by Swrve while a test is active is considered in result calculations.