yes
It is correct to write "Children's Day celebrations" because "Children's" is the possessive form indicating that the day belongs to the children.
Boss's day is the correct way to write it.
Yes, it is correct to write "Please reply by today" to indicate that you are requesting a response by the end of the day.
Valentine should be capitalised, because it's a name (St Valentine).Valentine's Day is the correct way to write it. Alternatively you can write Saint Valentine's Day, but that is not as popular as the shortened version.For example:"To my dearest wife, happy Valentine's Day""I like you, can I take you for a meal on Valentine's Day?"
Since I was born that day and told it was a Monday
10 May '10 is correct. The apostrophe before the 10 shows the omission of the 20 in the year 2010. In this date format, the day of the month comes first, then the month, then the year.
Not a correct shortened form of words. You should write/say 'It had'.
Since Joe Mama's real context is like saying your mother, Joe Mama was born on the day your mother was born.
It is correct to say "such an exhausting day", and not 'Such an exhaustive day'.
big write on every day is earth day
Teachers day is correct because it is for all teachers
Happy Name Day is correct.