Commas are almost always used to separate multiple components of an address or partial address. By "components", I mean, for example:
- building name and/or number
- street/road name
In the absence of a comma, it may be difficult for someone who is not familiar with the name or location to know which parts of the address belong together and which parts are distinct. For example, in the absence of commas, someone not familiar with the location may think that:
- Los is the name of an airport, in …
- a district called Angeles, in …
- a town called California.
(OK, that's not a very good example, but I hope it illustrates the point.)
One occasion when commas might be omitted in an address is when each component is written on a separate line, e.g. as is usually done on an envelope. Additionally, post codes (zip codes) may not be preceded and/or followed by commas.
For that reason, a comma is essential between "Los Angeles" & "California".
In my view, the remaining commas are optional, but:
- A comma is helpful to the reader between "California" and "on" because it indicates a break in the type of information being given, i.e. from address to date.
- Personally, I would omit the comma after "Friday", but then (as a Brit) I would also write the date & month in the opposite order, i.e. "Friday 29 October". In British practice, it used to be common to include a comma after the day of the week, but now it is at least as common to omit it: in our format, the digits make an obvious visual break between the day of the week and the month. Maybe a comma is still more common in US practice?