How soon can I apply for a 1-year extension on my Non-Immigrant O visa after my marriage visa expires?

The user inquired about the minimum waiting period to apply for a 1-year extension on a Non-Immigrant O visa, asking if 15 days is adequate or if at least 30 days is necessary. Community responses indicate that applications can be submitted before the 90-day visa expires, with some users sharing their experiences of submitting just days before expiry and receiving a 'under consideration' stamp.