ndiakon... First, of course, welcome to the board...
Second, that's an invalid query
1250 watts is the amount of power it requires to operate, and has no relationship with time whatsoever in itself.
To form it's *energy* consumption (what you're looking for), we multiply the power by time, usually hours.
1250 Watts * 1 hour = 1250 Watt-hours, or 1250Wh, or 1.25kWh.
So, in a nutshell, yes, by default, it would consume 1250 Watt-hours of energy in one hour. 2500Wh in 2 hours, and so on.