Delay from textfield xcode mac

How can I fix this error:

Sending 'NSString *_strong' to parameter of incompatible type 'NSTimeInterval' (aka 'double')

For this code:

NSString *PezaniTime = Pezani_CheckUpdatesAfterTime_TextField.stringValue;

[self performSelector:@selector(PezaniCheckVersionTime) withObject:@"" afterDelay:PezaniTime];