Hi Spring,

Your stitching is pretty good, except for the politeness. Here's my version.

We are grateful for your willingness to share the wealth of your knowledge with us. (In English culture, your version was too, too polite. My version is very polite, and sufficient. Too much politeness can seem a little 'foolish'.) We have scheduled  your presentations on the following dates and times:

John - Sept. 27 from 1:00 to 2:00 p.m.

Mira - Sept. 29 from 1:00 to 2:00 p.m.

Should the above schedule be inconvenient for you, please email us your preferred dates and times.

We are looking forward to your presentations.

Best wishes, Clive