How to change the data type in Logstash

Elastic Stack Logstash
5

@JeremyinNC @magnusbaeck @warkolm I have a colum name called DEPLOY_TIME ( like : 28-01-2015 19:33:44) , when it is indexing it into the ES it is mapping the type as string

"DEPLOY_TIME": {
"norms": {
"enabled": false
},
"type": "string",
"fields": {
"raw": {
"ignore_above": 256,
"index": "not_analyzed",
"type": "string"

I have also tried the date filter like

csv
  {
    
       columns => ["colum1", "colum2", "colum3", "DEPLOY_TIME"]
       separator => ";"}
	   
	   date
	   {
type => "mycsv" 
match => [ "DEPLOY_TIME", "DD-MM-YYYY HH:mm:ss" ] 
}
	   
  }

But it is still mapping DEPLOY_TIME as String ..
Any idea why and how can we resolve it ?