Shiva Purana
तेन ज्ञात्वा दिनं योगी प्राणायामपरः स्थितः ॥ स जयत्यागतं कालं मासार्द्धेनैव सुंदरि ॥ ३ ॥
Knowing the day through that, the Yogin stays engaged in Prāṇāyāma. O pretty woman, within half a month he conquers the Kāla that has already come upon him.
english translation
tena jJAtvA dinaM yogI prANAyAmaparaH sthitaH ॥ sa jayatyAgataM kAlaM mAsArddhenaiva suMdari ॥ 3 ॥
hk transliteration by Sanscript