So that’s what establishes your Blynk connection, and your code wont progress beyond that point until you have a connection to your WiFi and the Blynk server. If you are calculating the wrong values then the problem is with your code structure. @Toro_Blanco’s recommendation is a good one.
However, using Blynk.begin is a bad move for projects that use deep sleep, especially if your device is battery powered.
If you device can’t connect to either WiFi or the Blynk server - for whatever reason - then the code execution will stop at Blynk.begin and your device will never go back to sleep; flattening the battery in the process.
The structure used in this code is much better:
Pete.