I would bet you would not activate until April at a minimum. An email to planning is always advised but may not be helpful in determining an exact date.
Hard to judge as it depends on needs and staffing levels but it seems like a majority of guys get activated a month after the effective date, so end of April or probably for the May bid period.

I was surprised this bid came out already, so hard to tell when another shows up, most likely in less than 2 months another will show up.