/kloc-I have been to Changzhou within 0/4 days. Why does it always show Nanjing?

The communication big data travel card will directly display all the cities that users have stayed in within 14 days, instead of the travel information before 14 days. Although it is not displayed, it does not mean that the operator's data background will be directly deleted. The itinerary before 14 days cannot be found in the App or applet, but the operator can still find it in the background.

The user travel information collected by the communication big data travel card comes from operators such as China Mobile, China Telecom and China Unicom. It locates the user's location through the mobile phone token and the base station, obtains the city location, updates the data to the day after tomorrow, and then is found by the user.