Euh non, ce n’est pas évident pour férié notamment…
En cherchant sur Internet, j’ai trouvé un code pour Nodered 
Determine properties like holiday, business day, weekend, etc at the moment when message is received. (flow) - Node-RED adapté à la Slovénie 
Mais, au moins en France, les dates des jours fériés sont soient fixes soient dépendent de Pâques, j’ai adapté son code à la France.
J’ai également rajouté un « shift » pour avoir les infos sur un autre jour.
Et donc, en demandant la date 398 jours en arrière par rapport à aujourd’hui (2/2/21)
{ "_msgid":"6f5a1fc9.560d2", "payload":-398,"date":"2020-01-01T22:23:37.374Z", "holiday":true, "businessday":false, "weekend":false, "weekday":3, "leapyear":true, "holiday_name":"Jour de l'an", "properties":"holiday=true,businessday=false,weekend=false,weekday=3,leapyear=true" }
On voit que le 1er janvier 2020 est un jour férié et que c’était un mercredi…
Ou plus simplement pour demain (donc msg.payload égale 1):
[{"id":"18bb465c.d91d9a","type":"function","z":"f5b50430.ea48b8","name":"Propriété de la date","func":"/*\n\n * ----------------------------------------------------------------------------\n * \"THE BEER-WARE LICENSE\" (Revision 42):\n * github.com/mrizvic wrote this file. As long as you retain this notice you\n * can do whatever you want with this stuff. If we meet some day, and you think\n * this stuff is worth it, you can buy me a beer in return. M.Rizvic\n * ----------------------------------------------------------------------------\n * Avec une adaptation de R.Giraud pour la France - Mais ça ne mérite pas une bière\n * avec en plus la possibilté via msg.payload de demander une autre date + ou - X jours\n * par rapport à aujourd'hui\n\n## This function will pass incoming message to multiple outputs based on following conditions:\n## output 1 - unconditional\n## output 2 - if its holiday\n## output 3 - if its business day\n## output 4 - if its weeekend\n## output 5 - if its leap year\n\n## Holidays are defined in a matter of if..else if sentences as shown below in USER SPECIFIC DATES section. Some holidays are variable and must be calculated each time (e.g. easter)\n## Some properties will be appended to original message in case some would like to use them. Below is an example:\n\n_msgid: \"78a5e9f0.a318e8\"\ntopic: \"\"\npayload: 4\ndate: \"2017-02-23T15:59:59.401Z\"\nholiday: false\nbusinessday: true\nweekend: false\nweekday: 4\nleapyear: false\nproperties: \"holiday=false,businessday=true,weekend=false,weekday=4,leapyear=false\"\n\nweekday numbers are in range from 1 to 7 where is 1 for monday, 2 for tuesday, ... and 7 for sunday\ntariff can be 'vt' (high tariff) or 'mt' (low tariff)\n*/\n\nvar futur = msg.payload;\n// take current timestamp\nvar today = new Date();\nvar date = today.addDays(futur);\n\nvar getEasterDate = function(year) {\n var a = year % 19;\n var b = Math.floor(year / 100);\n var c = year % 100;\n var d = Math.floor(b / 4);\n var e = b % 4;\n var f = Math.floor((b + 8) / 25);\n var g = Math.floor((b - f + 1) / 3);\n var h = (19 * a + b - d - g + 15) % 30;\n var i = Math.floor(c / 4);\n var k = c % 4;\n var l = (32 + 2 * e + 2 * i - h - k) % 7;\n var m = Math.floor((a + 11 * h + 22 * l) / 451);\n var n0 = (h + l + 7 * m + 114);\n var n = Math.floor(n0 / 31) - 1;\n var p = n0 % 31 + 1;\n var date = new Date(year,n,p);\n return date;\n};\n\nDate.prototype.addDays = function(days)\n{\n var dat = new Date(this.valueOf());\n dat.setDate(dat.getDate() + days);\n return dat;\n};\n\nvar weekday = date.getDay();\nif (weekday === 0) { weekday = 7; }\n\nvar year = date.getFullYear();\nvar month = date.getMonth() + 1;\nvar day = date.getDate();\nvar hour = date.getHours();\n\nvar isHoliday = false;\nvar holidayString = \"\";\nvar isLeapYear = new Date(year, 1, 29).getMonth() == 1;\n\n// sunday or saturday\nvar isWeekend = (weekday > 5);\nvar isBusinessDay = ! isWeekend;\n\n\n// USER SPECIFIC DATES - BEGIN\n\n// Dimanche de Pâques\nvar easterDate = getEasterDate(year);\nvar ed1 = easterDate.getDate();\nvar em1 = easterDate.getMonth() + 1;\n\n// Lundi de Pâques\nvar easterMonday = easterDate.addDays(1);\nvar ed2 = easterMonday.getDate();\nvar em2 = easterMonday.getMonth() + 1;\n\n// Ascension = (Dimanche de Pâques + 39)\nvar ascension = easterDate.addDays(39);\nvar ad1 = ascension.getDate();\nvar am1 = ascension.getMonth() + 1;\n\n// Pentecôte\nvar pentecote = easterDate.addDays(50);\nvar pd1 = pentecote.getDate();\nvar pm1 = pentecote.getMonth() + 1;\n\n// set date specific properties\n\n if ( (month == 1) && (day == 1) ) { isHoliday = true; isBusinessDay = false; holidayString = \"Jour de l'an\"; }\nelse if ( (month == em1) && (day == ed1) ) { isHoliday = true; isBusinessDay = false; holidayString = \"Dimanche de Pâques\"; }\nelse if ( (month == em2) && (day == ed2) ) { isHoliday = true; isBusinessDay = false; holidayString = \"Lundi de Pâques\"; }\nelse if ( (month == 5) && (day == 1) ) { isHoliday = true; isBusinessDay = false; holidayString = \"Premier mai\"; }\nelse if ( (month == 5) && (day == 8) ) { isHoliday = true; isBusinessDay = false; holidayString = \"Armistice 39/45\"; }\nelse if ( (month == am1) && (day == ad1) ) { isHoliday = true; isBusinessDay = false; holidayString = \"Ascension\"; }\nelse if ( (month == pm1) && (day == pd1) ) { isHoliday = true; isBusinessDay = false; holidayString = \"Pentecôte\";}\nelse if ( (month == 7) && (day == 14) ) { isHoliday = true; isBusinessDay = false; holidayString = \"Fête Nationale\"; }\nelse if ( (month == 8) && (day == 15) ) { isHoliday = true; isBusinessDay = false; holidayString = \"Assomption\"; }\nelse if ( (month == 11) && (day == 1) ) { isHoliday = true; isBusinessDay = false; holidayString = \"Toussaint\"; }\nelse if ( (month == 11) && (day == 11) ) { isHoliday = true; isBusinessDay = false; holidayString = \"Armistice 14/18\"; }\nelse if ( (month == 12) && (day == 25) ) { isHoliday = true; isBusinessDay = false; holidayString = \"Noël\"; }\n\n// preserve original message\nvar result = msg;\nmsg.date = date;\n\n// add our properties\nresult.holiday = isHoliday;\nresult.businessday = isBusinessDay;\nresult.weekend = isWeekend;\nresult.weekday = weekday;\nresult.leapyear = isLeapYear;\nif (holidayString.length > 0) {\n result.holiday_name = holidayString;\n}\n\n// generate string of properties so one could\n// parse using switch node\nresult.properties = '';\nresult.properties += 'holiday=' + isHoliday + ',';\nresult.properties += 'businessday=' + isBusinessDay + ',';\nresult.properties += 'weekend=' + isWeekend + ',';\nresult.properties += 'weekday=' + weekday + ',';\nresult.properties += 'leapyear=' + isLeapYear;\n\n// generate conditional outputs\nmsg = result;\n\nreturn msg;\n","outputs":1,"noerr":0,"initialize":"","finalize":"","x":410,"y":2460,"wires":[["bb47b7a1.f10398"]]},{"id":"6e1cf6e6.e7c138","type":"inject","z":"f5b50430.ea48b8","name":"Demain","props":[{"p":"payload"}],"repeat":"","crontab":"","once":false,"onceDelay":"","topic":"","payload":"1","payloadType":"num","x":210,"y":2460,"wires":[["18bb465c.d91d9a"]]},{"id":"bb47b7a1.f10398","type":"debug","z":"f5b50430.ea48b8","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":590,"y":2460,"wires":[]}]
A adapter pour la Belgique avec les jours fériés locaux