<cffunction name="niceDate" returnType="string" output="no">
<cfargument name="pvm" type="date">
<cfargument name="maski" type="string">
<cfargument name="lang" type="string" default="en">
<cfif Find("mmm",maski) gt 0 and Find("mmmm",maski) eq 0>
<cfset kolme="true">
</cfif>
<cfset maski=Replace(maski, "dddd", UCase(DayOfWeekAsString(DayOfWeek(pvm))), "ALL")>
<cfset maski=Replace(maski, "ddd", UCase(Left(DayOfWeekAsString(DayOfWeek(pvm)), 3)), "ALL")>
<cfif Day(pvm) lt 10>
<cfset maski=Replace(maski, "dd", "0"&Day(pvm), "ALL")>
<cfelse>
<cfset maski=Replace(maski, "dd", Day(pvm), "ALL")>
</cfif>
<cfset maski=Replace(maski, "d", Day(pvm), "ALL")>
<cfset maski=Replace(maski, "mmmm", UCase(MonthAsString(Month(pvm))), "ALL")>
<cfset maski=Replace(maski, "mmm", UCase(Left(MonthAsString(Month(pvm)), 3)), "ALL")>
<cfif Month(pvm) lt 10>
<cfset maski=Replace(maski, "mm", "0"&Month(pvm), "ALL")>
<cfelse>
<cfset maski=Replace(maski, "mm", Month(pvm), "ALL")>
</cfif>
<cfset maski=Replace(maski, "m", Month(pvm), "ALL")>
<cfset maski=Replace(maski, "yyyy", Year(pvm), "ALL")>
<cfif Hour(pvm) lt 10>
<cfset maski=ReplaceNoCase(maski, "hh", "0"&Hour(pvm), "ALL")>
<cfelse>
<cfset maski=ReplaceNoCase(maski, "hh", Hour(pvm), "ALL")>
</cfif>
<cfset maski=ReplaceNoCase(maski, "h", Hour(pvm), "ALL")>
<cfif Minute(pvm) lt 10>
<cfset maski=ReplaceNoCase(maski, "nn", "0"&Minute(pvm), "ALL")>
<cfelse>
<cfset maski=ReplaceNoCase(maski, "nn", Minute(pvm), "ALL")>
</cfif>
<cfset maski=Replace(maski, "n", Minute(pvm), "ALL")>
<cfset maski=Replace(maski, "ss", Second(pvm), "ALL") />
<cfloop from="1" to="7" index="paiva">
<cfset maski=Replace(maski, UCase(DayOfWeekAsString(paiva)), DayOfWeekAsString(paiva), "ALL")>
<cfset maski=Replace(maski, Left(UCase(DayOfWeekAsString(paiva)), 3), Left(DayOfWeekAsString(paiva), 3), "ALL")>
</cfloop>
<cfloop from="1" to="12" index="kuukausi">
<cfset maski=Replace(maski, UCase(MonthAsString(kuukausi)), MonthAsString(kuukausi), "ALL")>
<cfset maski=Replace(maski, Left(UCase(MonthAsString(kuukausi)), 3), Left(MonthAsString(kuukausi), 3), "ALL")>
</cfloop>
<cfif lang is "fi">
<cfset maski=Replace(maski, "January", "tammikuuta", "ALL")>
<cfset maski=Replace(maski, "February", "helmikuuta", "ALL")>
<cfset maski=Replace(maski, "March", "maaliskuuta", "ALL")>
<cfset maski=Replace(maski, "April", "huhtikuuta", "ALL")>
<cfif isdefined("kolme")>
<cfset maski=Replace(maski, "May", "tou", "ALL")>
<cfelse>
<cfset maski=Replace(maski, "May", "toukokuuta", "ALL")>
</cfif>
<cfset maski=Replace(maski, "June", "kesäkuuta", "ALL")>
<cfset maski=Replace(maski, "July", "heinäkuuta", "ALL")>
<cfset maski=Replace(maski, "August", "elokuuta", "ALL")>
<cfset maski=Replace(maski, "September", "syyskuuta", "ALL")>
<cfset maski=Replace(maski, "October", "lokakuuta", "ALL")>
<cfset maski=Replace(maski, "November", "marraskuuta", "ALL")>
<cfset maski=Replace(maski, "December", "joulukuuta", "ALL")>
<cfset maski=Replace(maski, "Jan", "tam", "ALL")>
<cfset maski=Replace(maski, "Feb", "hel", "ALL")>
<cfset maski=Replace(maski, "Mar", "maa", "ALL")>
<cfset maski=Replace(maski, "Apr", "huh", "ALL")>
<cfset maski=Replace(maski, "Jun", "kes", "ALL")>
<cfset maski=Replace(maski, "Jul", "hei", "ALL")>
<cfset maski=Replace(maski, "Aug", "elo", "ALL")>
<cfset maski=Replace(maski, "Sep", "syy", "ALL")>
<cfset maski=Replace(maski, "Oct", "lok", "ALL")>
<cfset maski=Replace(maski, "Nov", "mar", "ALL")>
<cfset maski=Replace(maski, "Dec", "jou", "ALL")>
<cfset maski=Replace(maski, "Monday", "maanantai", "ALL")>
<cfset maski=Replace(maski, "Tuesday", "tiistai", "ALL")>
<cfset maski=Replace(maski, "Wednesday", "keskiviikko", "ALL")>
<cfset maski=Replace(maski, "Thursday", "torstai", "ALL")>
<cfset maski=Replace(maski, "Friday", "perjantai", "ALL")>
<cfset maski=Replace(maski, "Saturday", "lauantai", "ALL")>
<cfset maski=Replace(maski, "Sunday", "sunnuntai", "ALL")>
<cfset maski=Replace(maski, "Mon", "ma", "ALL")>
<cfset maski=Replace(maski, "Tue", "ti", "ALL")>
<cfset maski=Replace(maski, "Wed", "ke", "ALL")>
<cfset maski=Replace(maski, "Thu", "to", "ALL")>
<cfset maski=Replace(maski, "Fri", "pe", "ALL")>
<cfset maski=Replace(maski, "Sat", "sa", "ALL")>
<cfset maski=Replace(maski, "Sun", "su", "ALL")>
<cfelseif lang is "sv" or lang is "swe">
<cfset maski=Replace(maski, "January", "januari", "ALL")>
<cfset maski=Replace(maski, "February", "februari", "ALL")>
<cfset maski=Replace(maski, "March", "mars", "ALL")>
<cfset maski=Replace(maski, "April", "april", "ALL")>
<cfif isdefined("kolme")>
<cfset maski=Replace(maski, "May", "maj", "ALL")>
<cfelse>
<cfset maski=Replace(maski, "May", "maj", "ALL")>
</cfif>
<cfset maski=Replace(maski, "June", "juni", "ALL")>
<cfset maski=Replace(maski, "July", "juli", "ALL")>
<cfset maski=Replace(maski, "August", "augusti", "ALL")>
<cfset maski=Replace(maski, "September", "september", "ALL")>
<cfset maski=Replace(maski, "October", "oktober", "ALL")>
<cfset maski=Replace(maski, "November", "november", "ALL")>
<cfset maski=Replace(maski, "December", "december", "ALL")>
<cfset maski=Replace(maski, "Jan", "jan", "ALL")>
<cfset maski=Replace(maski, "Feb", "feb", "ALL")>
<cfset maski=Replace(maski, "Mar", "mar", "ALL")>
<cfset maski=Replace(maski, "Apr", "apr", "ALL")>
<cfset maski=Replace(maski, "Jun", "jun", "ALL")>
<cfset maski=Replace(maski, "Jul", "jul", "ALL")>
<cfset maski=Replace(maski, "Aug", "aug", "ALL")>
<cfset maski=Replace(maski, "Sep", "sep", "ALL")>
<cfset maski=Replace(maski, "Oct", "okt", "ALL")>
<cfset maski=Replace(maski, "Nov", "nov", "ALL")>
<cfset maski=Replace(maski, "Dec", "dec", "ALL")>
<cfset maski=Replace(maski, "Monday", "måndag", "ALL")>
<cfset maski=Replace(maski, "Tuesday", "tisdag", "ALL")>
<cfset maski=Replace(maski, "Wednesday", "onsdag", "ALL")>
<cfset maski=Replace(maski, "Thursday", "torsdag", "ALL")>
<cfset maski=Replace(maski, "Friday", "fredag", "ALL")>
<cfset maski=Replace(maski, "Saturday", "lördag", "ALL")>
<cfset maski=Replace(maski, "Sunday", "söndag", "ALL")>
<cfset maski=Replace(maski, "Mon", "må", "ALL")>
<cfset maski=Replace(maski, "Tue", "ti", "ALL")>
<cfset maski=Replace(maski, "Wed", "on", "ALL")>
<cfset maski=Replace(maski, "Thu", "to", "ALL")>
<cfset maski=Replace(maski, "Fri", "fr", "ALL")>
<cfset maski=Replace(maski, "Sat", "lö", "ALL")>
<cfset maski=Replace(maski, "Sun", "sö", "ALL")>
<cfelseif lang neq "en" and lang neq "eng" and isdefined("translations.general.dateStuff.listOfMonths")>
<cfset maski=Replace(maski, "January", ListGetAt(translations.general.dateStuff.listOfMonths, 1), "ALL")>
<cfset maski=Replace(maski, "February", ListGetAt(translations.general.dateStuff.listOfMonths, 2), "ALL")>
<cfset maski=Replace(maski, "March", ListGetAt(translations.general.dateStuff.listOfMonths, 3), "ALL")>
<cfset maski=Replace(maski, "April", ListGetAt(translations.general.dateStuff.listOfMonths, 4), "ALL")>
<cfif isdefined("kolme")>
<cfset maski=Replace(maski, "May", Left(Trim(ListGetAt(translations.general.dateStuff.listOfMonths, 5)), 3), "ALL")>
<cfelse>
<cfset maski=Replace(maski, "May", ListGetAt(translations.general.dateStuff.listOfMonths, 5), "ALL")>
</cfif>
<cfset maski=Replace(maski, "June", ListGetAt(translations.general.dateStuff.listOfMonths, 6), "ALL")>
<cfset maski=Replace(maski, "July", ListGetAt(translations.general.dateStuff.listOfMonths, 7), "ALL")>
<cfset maski=Replace(maski, "August", ListGetAt(translations.general.dateStuff.listOfMonths, 8), "ALL")>
<cfset maski=Replace(maski, "September", ListGetAt(translations.general.dateStuff.listOfMonths, 9), "ALL")>
<cfset maski=Replace(maski, "October", ListGetAt(translations.general.dateStuff.listOfMonths, 10), "ALL")>
<cfset maski=Replace(maski, "November", ListGetAt(translations.general.dateStuff.listOfMonths, 11), "ALL")>
<cfset maski=Replace(maski, "December", ListGetAt(translations.general.dateStuff.listOfMonths, 12), "ALL")>
<cfset maski=Replace(maski, "Jan", Left(Trim(ListGetAt(translations.general.dateStuff.listOfMonths, 1)), 3), "ALL")>
<cfset maski=Replace(maski, "Feb", Left(Trim(ListGetAt(translations.general.dateStuff.listOfMonths, 2)), 3), "ALL")>
<cfset maski=Replace(maski, "Mar", Left(Trim(ListGetAt(translations.general.dateStuff.listOfMonths, 3)), 3), "ALL")>
<cfset maski=Replace(maski, "Apr", Left(Trim(ListGetAt(translations.general.dateStuff.listOfMonths, 4)), 3), "ALL")>
<cfset maski=Replace(maski, "Jun", Left(Trim(ListGetAt(translations.general.dateStuff.listOfMonths, 6)), 3), "ALL")>
<cfset maski=Replace(maski, "Jul", Left(Trim(ListGetAt(translations.general.dateStuff.listOfMonths, 7)), 3), "ALL")>
<cfset maski=Replace(maski, "Aug", Left(Trim(ListGetAt(translations.general.dateStuff.listOfMonths, 8)), 3), "ALL")>
<cfset maski=Replace(maski, "Sep", Left(Trim(ListGetAt(translations.general.dateStuff.listOfMonths, 9)), 3), "ALL")>
<cfset maski=Replace(maski, "Oct", Left(Trim(ListGetAt(translations.general.dateStuff.listOfMonths, 10)), 3), "ALL")>
<cfset maski=Replace(maski, "Nov", Left(Trim(ListGetAt(translations.general.dateStuff.listOfMonths, 11)), 3), "ALL")>
<cfset maski=Replace(maski, "Dec", Left(Trim(ListGetAt(translations.general.dateStuff.listOfMonths, 12)), 3), "ALL")>
<cfset maski=Replace(maski, "Monday", ListGetAt(translations.general.dateStuff.listOfWeekdays, 2), "ALL")>
<cfset maski=Replace(maski, "Tuesday", ListGetAt(translations.general.dateStuff.listOfWeekdays, 3), "ALL")>
<cfset maski=Replace(maski, "Wednesday", ListGetAt(translations.general.dateStuff.listOfWeekdays, 4), "ALL")>
<cfset maski=Replace(maski, "Thursday", ListGetAt(translations.general.dateStuff.listOfWeekdays, 5), "ALL")>
<cfset maski=Replace(maski, "Friday", ListGetAt(translations.general.dateStuff.listOfWeekdays, 6), "ALL")>
<cfset maski=Replace(maski, "Saturday", ListGetAt(translations.general.dateStuff.listOfWeekdays, 7), "ALL")>
<cfset maski=Replace(maski, "Sunday", ListGetAt(translations.general.dateStuff.listOfWeekdays, 1), "ALL")>
<cfset maski=Replace(maski, "Mon", Left(Trim(ListGetAt(translations.general.dateStuff.listOfWeekdays, 1)), 2), "ALL")>
<cfset maski=Replace(maski, "Tue", Left(Trim(ListGetAt(translations.general.dateStuff.listOfWeekdays, 2)), 2), "ALL")>
<cfset maski=Replace(maski, "Wed", Left(Trim(ListGetAt(translations.general.dateStuff.listOfWeekdays, 3)), 2), "ALL")>
<cfset maski=Replace(maski, "Thu", Left(Trim(ListGetAt(translations.general.dateStuff.listOfWeekdays, 4)), 2), "ALL")>
<cfset maski=Replace(maski, "Fri", Left(Trim(ListGetAt(translations.general.dateStuff.listOfWeekdays, 5)), 2), "ALL")>
<cfset maski=Replace(maski, "Sat", Left(Trim(ListGetAt(translations.general.dateStuff.listOfWeekdays, 6)), 2), "ALL")>
<cfset maski=Replace(maski, "Sun", Left(Trim(ListGetAt(translations.general.dateStuff.listOfWeekdays, 7)), 2), "ALL")>
</cfif>
<cfreturn maski>
</cffunction>
Here’s the entire ancient code. I know it is goddamn unsophisticated and in many ways hideous piece of code, but hey, it worked for us for more than a decade 
So, yeah, I assume running that once wont do much difference. But we had templates where the same function is/was used, say, for 200 times (listing software downloads older versions, for example, and when each version was originally updated) it seemed to slow down the processing ridiculously with Lucee.
And yeah, there might be some obvious gotchas there in the code that could’ve been improved by better testing/ thinking it properly. But as the function is not needed anymore, as LSDateTimeFormat() now works as it should, we aren’t too interested to think about it.
The €0.02 here is that many of us might have ancient code in various places and you kinda expect them to run at least on par with other CFML engines, not slower 