End-Of-Month

The End-Of-Month - abbreviated as EOM - is a convention that affects the determination of the end date T of a time interval [T₀,T] out of a given start date T₀ and interval length L expressed in months or years.
EOM can be relevant only if T₀ falls on the last business day of a month.
For example, EOM is considered if T₀ = 26 Feb 2021 (Friday), but not if T₀ = 25 Feb 2021 (Thursday)
If EOM applies, the rule is that if the nominal date T' = T₀ + L produced by shifting T₀ by L does not fall on the last business day of its containing month, must be further shifted to a final date T that does so.
For example, take T₀ = 26 Feb 2021 (Friday) and L = 1 month
Then T' = T₀ + L = 26 Mar 2021 (Friday) is not the last business day of the month of March and must be therefore shifted to the date T = 31 Mar 2021 (Wednesday)