Tier 2 dependent visa extension when tier 2 main applicant obtained ILR

[Richie1]

Hello

I have dependent tier 2 visa which will expire this April and I will be eligible to apply for ILR this September. My wife (tier 2 main applicant) had tier 2 visa and obtained ILR last year.

When I pay immigration health surcharge, I have to put down work start date and end date like below

Could you please let me know what it means exactly in my case? (Does it mean my wife's tier2 visa period? issue date & valid until? or from today to after 3 years)

Visa route: Dependent
Visa type: Skilled Worker (Dependant) 3 Year
Work start:
Work end:

Thank you

[CR001]

uk-tier-2-employer-sponsored-visas/tier ... l#p1979260