PHEither can be correct, depending on the idea you want to E×ρréšš.
”On that day, which was a Tuesday, my sister and I went to the store together.”
”In that day, before antibiotics had been discovered, many people died from diseases which are now curable.”
”On that day” refers to one particular day, a specific date.
”In that day” refers to a time period, usually to contrast it with another, especially the current, time period.
”On that day, which was a Tuesday, my sister and I went to the store together.”
”In that day, before antibiotics had been discovered, many people died from diseases which are now curable.”
”On that day” refers to one particular day, a specific date.
”In that day” refers to a time period, usually to contrast it with another, especially the current, time period.