Conditional parking restrictions - syntax?

(Way History: ‪East 57th Street‬ (‪1271733794‬) | OpenStreetMap)

I have just added parking restrictions on the way linked above, but JOSM gives warnings for syntax errors. I added restrictions on 58th Street south of the elementary school also (just southwest of the way noted above). I tried three different syntaxes for the school day restrictions and JOSM gives warnings on all of them.

This is the first time I’ve tried to map on-street parking, which is generally allowed in this neighborhood. I think it’s not desirable to tag explicitly as allowed everywhere, though, since that’s normal on similar neighborhood streets. I’m only tagging the restrictions, but I want to make sure I’m doing it correctly before I continue.

In words, explaining the restrictions on East 57th Street for the first block east of the school:
There is no parking allowed between 7am and 3pm on school days on the north side of the street, and there is no parking allowed between 2pm and 3pm on school days on the south side of the street.

I have edited it, but still get the syntax warnings.

I added parking:both=lane on East 57th Street and changed it to the syntax as in the comments, with SH off. On East 58th Street I left out the SH off, but still got the same warning.
Screenshot 2024-04-11 114625

However, one of the replies from skyper includes a link to a JOSM bug description saying this is incorrectly flagged as a warning, and the syntax is actually correct. Is the ; SH off correct too? I see a comment saying skyper got it wrong/backwards at first, but I think the comments were corrected before I saw them.

Technically =no_parking @ ("07:00-15:00 School days") is valid syntax for comments, only not an effective one. Your warning must have come from having 2 @ there.
For clarity from what’s mentioned, it’s parking:left:restriction:conditional=no_parking @ (Mo-Fr 07:00-15:00; SH off) + parking:right:restriction:conditional=no_parking @ (Mo-Fr 14:00-15:00; SH off) to override it. However, the problem is SH actually needs to be defined, and it’s per jurisdiction. Most are currently generated from other websites, for the few that have been added. GitHub - opening-hours/opening_hours.js: Library to parse and process the opening_hours tag from OpenStreetMap data
Ps you (and I) are looking at the sides wrongly. You should look at the triangle arrows on the lines.

parking:left:restriction:conditional=no_parking @ (Mo-Fr 14:00-15:00; SH off)
parking:right:restriction:conditional=no_parking @ (Mo-Fr 07:00-15:00; SH off) 

Using your example Way: ‪East 57th Street‬ (‪1271733794‬) | OpenStreetMap, I get two warnings:

I would add the common situation, too, together with the restrictions. In this case the road is mapped from west to east:

parking:both=* (might be one of "lane", "street_side", "on_kerb", "half_on_kerb")
parking:left:restriction:conditional=no_parking @ (Mo-Fr 07:00-15:00; SH off)
parking:right:restriction:conditional=no_parking @ (Mo-Fr 14:00-15:00; SH off)

Se skyper comment above