How to assign current week # to events?

[atebysandwich]

I have a list of events that happened over the last couple of weeks but the will be appended as it will be ran each week. I would like to create a search to show the number week of the year corresponding with the event. 

I was was thinking something like this, but it applies to all events regardless of the time stamp. 

| eval Current_Week=tonumber(strftime(now(),"%V"))

I understand I need to add more to the eval command to compare time of the event. 

[yuanliu]

Do you mean this?  Not clear what was the desired result.

| eval Then_Week=tonumber(strftime(_time,"%V"))