Is the supplication, "O Allah, indeed You are an Pardoner, You love pardon, so pardon me," to be recited only during the last ten nights, or throughout the entire day, both day and night?

Asking Allah for pardon (al-Afw) and well-being (al-Afiyah) is permissible at all times, as it encompasses the good of both this world and the Hereafter. It is not exclusively for Laylat al-Qadr or the last ten nights of Ramadan. The Prophet (peace be upon him) recommended it, and it is among the litanies and supplications that a Muslim should maintain morning and evening. Due to the immense status of pardon (al-Afw), it is fitting that it be the greatest request on Laylat al-Qadr, because supplications on that night are answered. This does not mean that it should not be recited during the day of the last ten nights or at other times.