If you have an issue with times showing differently in the mobile app to what was rostered, this is mostly likely caused by the timezone on your phone set differently to what is setup for your Branch in Brevity.
While logged in as an Administrator in Brevity, navigate to Administration > Branch Setup. Ensure the correct timezone is set here.
Please refer to the guide of the following link https://support.apple.com/en-us/HT203483.
In short, you should ensure the correct timezone is set for your device in Settings > General > Date & Time > Time Zone.
Please refer to the guide of the following link https://support.google.com/android/answer/2841106?hl=en .
In short, you should ensure the correct timezone is set for your device in Settings > System > Date & Time > Automatic Time Zone.