You have, as said in the Puranas, taken your birth seven times in the womb of Aditi. You also took birth in the womb of Prishni. The learned say that you are the three Yugas.
अदित्याः सप्तधा त्वं तु पुराणो गर्भतां गतः। पृश्निगर्भस्त्वमेवैकस्त्रियुगं त्वां वदन्त्यपि॥