Direct link to add specific google calendar event

https://calendar.google.com/calendar/render?action=TEMPLATE&pli=1&sf=true&output=xml& text=[Event_Title]& details=[Event_Details]&location=[Event_Location]& dates=[From_Date_Time]/[To_Date_time]

for e.g

https://calendar.google.com/calendar/render?action=TEMPLATE&pli=1&sf=true&output=xml&text=Sample Event&details=Sample Events Details &location=Location&dates=20151208T180000Z/20151208T191500Z

Dates are given YYYYMMDDTHHMMSSZ format, use GMT time, google automatically convert into your calendar default one