Timing LCA and H1B to apply on April 1st

Please advise on the following:

Do employment dates on the LCA and H1B applications for a specific employee have to match exactly?
It seems to be impossible if aiming to send in H1B application on April 1st: Employment can’t begin earlier than October 1st, and when filing the LCA, beginning employment date must be no earlier than 6 month from the date of filing. So LCA needs to be filed on April 1st too…But then H1B application will need to be filed later than April 1st which seems to be too late for the application to fit in the cap…
Your help regarding timing of LCA and H1B would help tremendously!

Thank you!

Hypothetical example

You have LCA valid for 3 years from Sep 15, 2016 to Sep 14, 2019. This was applied on Mar 15 (6 months in advance)

When filling I-129, you can mention start date as Oct 1, 2016 and end date as Sep 14, 2019.

So your dates are still within the LCA date range.

Awesome, thank you so much for assistance!

Sincere regards,
NataS