The Day when all the secrets (deeds, prayers, fasting, etc.) will be

﴿يَوۡمَ تُبۡلَى ٱلسَّرَآئِرُ ﴾
[الطَّارق: 9]

The Day when all the secrets (deeds, prayers, fasting, etc.) will be examined (as to their truth)

﴿يوم تبلى السرائر﴾ [الطَّارق: 9]

Al Bilal Muhammad Et Al
The day that all things secret will be tested

Ali Bakhtiari Nejad
a day that the secrets are disclosed

Ali Quli Qarai
on the day when the secrets are examined

Ali Unal
On the Day when all things (that remained or were kept) secret will be made manifest

Hamid S Aziz
On the day when the secrets shall be tried

John Medows Rodwell
On the day when all secrets shall be searched out

Literal
A day/time the secrets/intentions be tested

Mir Anees Original
the day, (when) secrets will be examined

Mir Aneesuddin
the day, (when) secrets will be examined