Hi Rabbi, We found a talis with a silver atarah on it near a park… It was kind of folded on the stair wall ledge. We had no one to ask around. My kid came to the shul to ask me. (I wasn’t with the family.) In the end my wife put the atarah underneath the tallis so it wasn’t visible… then after shabbos we put up a sign near where the tallis was, and on the street, and now we have the tallis… How long is the hachrazah for this item? How often do we need to check the signs.
There is no specific time limit for this, and if it hasn’t worked for two weeks it looks like the sign isn’t helping.
However, the Shulchan Aruch (267:3) rules that the place for the declaration is local shuls, and certainly for a tallis it is wise to declare the find in shul.
Hopefully, this will help find the owner.
Good luck and best wishes.