"This is the month of March."
Translation:ʻO kēia ka mahina ʻo Malaki.
The word before the name of the month was ʻo with ʻokina since it is identifying the name of the month.
"This is the month, January." = "ʻO kēia ka mahina ʻo Ianuali."
(This information came from (Hawaiian Language Fundamentals | ʻŌLELO ʻŌIWI | MOKUNA 1: Māhele 4....ʻaoʻao 35)
ʻO ka mahina hea kēia? = What (which) month is this?
ʻO kēia ka mahina ʻo Iune. = This is the month, June. Or = This is the month of June.
ʻO Iune kēia. = This is June.
ʻO Iune kēia mahine. = This month is June.
I am going to add the rest of the explanation from the book source. In the next two sets of sentences, the word (o) does not begin with an ʻokina since it is stating that the date belongs to that month. This may be confusing since the word (o) is often translated as of, and even though this is also the case in the first set ABOVE, it actually identifies A NAME rather than any sense of possession.
ʻO ka lā ʻehia kēia? = What day of the month is this?
ʻO ka lā ʻeono kēia o Malaki. = This is March sixth.
I ka lā ʻehia? = On what day of the month?
I ka lā ʻelua o Ianuali. = On January second.
(I think that the monthʻs name acts like a personʻs name in this case.)
ʻO kēia ke kāne ʻo Ronnie. = This is the man, Ronnie.
(perhaps) ʻO Ronnie kēia. = This is Ronnie.
ʻO Ronnie kēia kāne. = Ronnie is this man.
I found more information on how the month is like a name. Look at time segment [2:34] to [2:49] in the video (Ka Leo ʻŌiwi | Episode 11)
(Video link) https://youtu.be/fpWk5Yl8H84
ʻO wai kēia mahina? = What is this month?
(OR literal translation: Who is this month?
ʻO Kepakemapa kēia mahine. = This month is September.