Updated April 8, 2019
Feature
The Date.Time Calculator stores the last 20 steps of button operation and its result to implement the UNDO function. This information is recorded in the Date.Time Calculator App-specific storage area on the device you are working with.
The App does not send this information outside of the device. You can not access this information from apps other than this app. Because this information is the target when backing up a device, the backup and its restoration will copy it to another device.
This App has no access to any other information, including your personal information.