Terraform module to change a timestamp's timezone

time_to_utc.tf

# This module transforms the time variable into an
# RFC 3339 formated date in UTC timezone
locals {
  time_ZZZZZ = formatdate(
    "YYYY-MM-DD'T'hh:mm:ssZZZZZ",
    var.time)
  time_zoneless = formatdate(
    "YYYY-MM-DD'T'hh:mm:ss",
    var.time)
  time_zone_sign = substr(
    local.time_ZZZZZ,
    length(local.time_zoneless),
    1)
  time_zone = substr(
    local.time_ZZZZZ,
    length(local.time_zoneless) + 1,
    -1)
  time_diff = "${
    replace(local.time_zone, ":", "h")
  }m"
  time_UTC = timeadd(
    "${local.time_zoneless}+00:00",
    "${
      local.time_zone_sign == "+"
        ? "-"
        : "+"
    }${local.time_diff}")
}

output "utc" {
  description = "Time converted to UTC"
  value = local.time_UTC
}

variable "time" {
  description = "Time to be converted to UTC"
}