Unix Timestamp Calendly Appt Date

Unix Timestamp Calendly Appt Date

Hello, 

I need to create a function that will convert/return my date from Calendly in the following format: "2022-08-10T14:00:00.000000Z" to a UTC timestamp value in milliseconds. Can someone help? 

I tried the following: 
string UnixDate(string myTime, string unixTime)
{
unixTime = myTime.unixEpoch();
return unixTime;
}
However, the API client I am sending it to is viewing it in the wrong time zone. Not sure what I am doing wrong. I would really appreciate any support. 

I feel so frustrated with this. I have been trying to find a way to convert this appointment date from Calendly with a custom function into a UNIX Timestamp for the past 5 hours.