Hiru nare ya mi zo magaetsuru tsukikage o kyō to ya iwamu kinō to ya iwan - Gosen Wakashu(English Translation & Meaning)

昼なれや見ぞまがへつる月影を
今日とや言はむ昨日とや言はん

Roma-ji: Hiru nare ya mi zo magaetsuru tsukikage o kyō to ya iwamu kinō to ya iwan
English Translation: Is it day? I wonder—
so I mistook the moonlight
shining here tonight;
shall I call this hour today,
or call it yesterday
Meaning: Is it daytime? So I mistook this moonlight. Shall I call this hour today, or shall I call it yesterday?
Commentary: Book Fifteen Miscellaneous Poems I 1100

Headnote: "On seeing how lovely the moon was."
The poet says the moonlight was so bright he mistook it for day, and wonders whether to call the hour today or yesterday. Before a moon still bright as noon deep in the night, he praises its beauty with the wit of losing even the boundary between days.
According to the headnote, it was composed on seeing how lovely the moon was. Like the opening poem of the Kokinshu, "Toshi no uchi ni haru wa kinikeri hitotose o kozo to ya iwan kotoshi to ya iwan," it sets two words side by side and cannot choose between them.
The poet, "Mitsune," is Ōshikōchi no Mitsune. One of the compilers of the Kokinshu, he is counted among the Thirty-Six Poetic Immortals. The Ogura Hyakunin Isshu includes his poem "Kokoroate ni oraba ya oramu hatsushimo no."

The first line, "Hiru nare ya," means "is it day," with "ya" a question. He treats the moon's brightness as daylight.
The second line, "mi zo magaetsuru," means "so I mistook it," with "zo" an emphatic binding particle closed by the attributive "tsuru." The poem pauses here.
The third line, "tsukikage o," means "the moonlight."
The fourth line, "kyō to ya iwamu," means "shall I call it today," with "ya" an interrogative binding particle.
The last line, "kinō to ya iwan," means "or shall I call it yesterday," repeating the form of the fourth line as a parallel. It shows his sense that, in the late night's bright moonlight, he cannot tell where one day ends.
Author: Oshikochi no Mitsune
Source: Gosen Wakashu
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