Next window period ,for major earthquake is 17th April 2011. window period is + or - one day.Time in UTC.
The quake could be 6.5+
Now narrowing in on time ,it could be like this
1) 16th April---0300 UTC
2) 17th April---1030 UTC
3) 18th April---0330 UTC
These are the probable times. May be more than one quake
Place not known