The relevant leap years are 2000, 2004, 2008, 2012. Remaining 11 years have 365 days. So there are 15×365+4=5479 days in exactly 15 years. This takes us to 23 March 2014. There are 5479×24×60×60=473385600 seconds in 5479 days.
Between 23 March and 3 April there are 11 days=11×24×60×60=950400 seconds.
Between 01:17 and 10:30 the time difference is 9hr 13min=9×3600+13×60=33180 seconds.
So in total we have 473385600+950400+33180=474,369,180 seconds