diff --git a/src/stages.js b/src/stages.js
new file mode 100644
index 0000000..1248570
--- /dev/null
+++ b/src/stages.js
@@ -0,0 +1,149 @@
+import exec from 'k6/execution'
+
+// parseDuration parses the provided string as an Integer number
+// in millisecond precision
+function parseDuration(str) {
+	if (str == null || str.length < 1) {
+		throw new Error('str is empty')
+	}
+
+	// the sum in millisecond of the parsed duration
+	let d = 0;
+
+	// current contains the partial seen number
+	// it's reset when a time unit is found
+	let current = '';
+
+	
+	// it tracks the seen time units
+	// and it denies eventual duplicated
+	let seen = {}
+
+	for (let i = 0; i < str.length; i++) {
+		// append the current char if it's a number or a decimal separator
+		if (isNumber(str[i]) || str[i] == '.') {
+			current += str[i]
+		}
+
+		// return if the next char is not a time unit 
+		if (str[i+1] == null || isNumber(str[i+1]) || str[i+1] == '.') {
+			continue
+		}
+	
+		let v = parseFloat(current, 10)
+		let next = str[i+1]
+		
+		switch (next) {
+			case 'd':
+				d += v*24*60*60*1000
+				break;
+			case 'h':
+				d += v*60*60*1000
+				break;
+			case 'm':
+				if (i + 2 < str.length && str[i+2] == 's') {
+					// millisecond is the maximum precision
+					// truncate eventual decimal
+					d += Math.trunc(v)
+					i++
+					next = 'ms'
+				} else {
+					d += v*60*1000
+				}
+				break;
+			case 's':
+				d += v*1000
+				break;
+			default:
+				throw new Error(`${next} is an unsupported time unit`)
+		}
+		if (seen[next]) {
+			throw new Error(`${next} time unit is provided multiple times`)
+		}
+		seen[next] = true
+		i++
+		current = ''
+	}
+	// flush in case no time unit has been provided
+	// for the latest group
+	if (current.length > 0) {
+		d += parseFloat(current, 10)
+	}
+	return d 
+}
+
+// isNumber return true if the c character is a number
+function isNumber(c) {
+	return c >= '0' && c <= '9'
+}
+
+// getCurrentStageIndex returns the computed index of the running stage.
+function getCurrentStageIndex() {
+	let scenario = exec.test.options.scenarios[exec.scenario.name]
+	if (scenario == null)	{
+		throw new Error(`the exec.test.options object doesn't contain the current scenario ${exec.scenario.name}`)
+	}
+	if (scenario.stages == null) {
+		throw new Error(`only ramping-vus or ramping-arravial-rate supports stages, it is not possible to get a stage index on other executors.`)
+	}
+
+	if (scenario.stages.length < 1) {
+		throw new Error(`the current scenario ${scenario.name} doesn't contain any stage`)
+	}
+
+	let sum = 0;
+	let elapsed = new Date() - exec.scenario.startTime
+	for (let i = 0; i < scenario.stages.length; i++) {
+		sum += parseDuration(scenario.stages[i].duration)
+		if (elapsed < sum) {
+			return i
+		}
+	}
+
+	return scenario.stages.length-1
+}
+
+// tagWithCurrentStageIndex adds a tag with a `stage` key
+// and the index of the current running stage as value.
+function tagWithCurrentStageIndex() {
+  exec.vu.tags['stage'] = getCurrentStageIndex()
+}
+
+// tagWithCurrentStageProfile adds a tag with a `stage` key
+// and the profile (ramp-up, steady or ramp-down) computed
+// from the current running stage.
+function tagWithCurrentStageProfile() {
+  //ramp-up when previous.target < current.target
+  //ramp-down when previous.target > current.target
+  //steady when prevuious.target = current.target
+	
+	let getStageProfile = function() {	
+		let currentIndex = getCurrentStageIndex()
+		if (currentIndex < 1) {
+			return 'ramp-up'
+		}
+
+		let stages = exec.test.options.scenarios[exec.scenario.name].stages
+		let current = stages[currentIndex]
+		let previous = stages[currentIndex-1] 
+
+		if (current.target  > previous.target) {
+			return 'ramp-up'
+		}
+		
+		if (previous.target == current.target) {
+			return 'steady'
+		}
+
+		return 'ramp-down'
+	}
+
+  exec.vu.tags['stage_profile'] = getStageProfile()
+}
+
+export {
+	parseDuration,
+	getCurrentStageIndex,
+	tagWithCurrentStageIndex,
+	tagWithCurrentStageProfile,
+}
diff --git a/tests/stages.js b/tests/stages.js
new file mode 100644
index 0000000..27034d0
--- /dev/null
+++ b/tests/stages.js
@@ -0,0 +1,247 @@
+import { describe, expect } from 'https://jslib.k6.io/k6chaijs/4.3.4.0/index.js'
+import exec from 'k6/execution'
+import { sleep } from 'k6'
+
+import {
+	parseDuration,
+	getCurrentStageIndex,
+	tagWithCurrentStageIndex,
+	tagWithCurrentStageProfile,
+} from '../src/stages.js'
+
+
+export let options = {
+	scenarios: {
+		'parseDuration': {
+			executor: 'shared-iterations',
+			iterations: 1,
+			exec: 'testParseDuration'
+		},
+		'getCurrentStageIndex': {
+			executor: 'ramping-vus',
+			stages: [
+				{ duration: "1s10ms", target: 1 },
+				{ duration: "1s", target: 1 },
+			],
+			exec: 'testGetCurrentStageIndex'
+		},
+		'tagWithCurrentStageIndex': {
+			executor: 'ramping-vus',
+			stages: [
+				{ duration: "1s", target: 1 },
+				{ duration: "1s", target: 1 },
+			],
+			exec: 'testTagWithCurrentStageIndex'
+		},
+		'tagWithRampUpWhenOnlyOne': {
+			executor: 'ramping-vus',
+			stages: [
+				{ duration: "0.1s", target: 1 }
+			],
+			exec: 'testTagWithRampUpProfileWhenOnlyOne'
+		},
+		'tagWithRampUp': {
+			executor: 'ramping-vus',
+			stages: [
+				{ duration: "0.1s", target: 1 },
+				{ duration: "0.1s", target: 2 }
+			],
+			exec: 'testTagWithRampUp'
+		},
+		'tagWithSteady': {
+			executor: 'ramping-vus',
+			stages: [
+				{ duration: "0.1s", target: 1 },
+				{ duration: "0.1s", target: 1 }
+			],
+			exec: 'testTagWithSteady'
+		},
+		'tagWithRampDown': {
+			executor: 'ramping-vus',
+			stages: [
+				{ duration: "0.1s", target: 2 },
+				{ duration: "0.1s", target: 1 }
+			],
+			exec: 'testTagWithRampDown'
+		},
+	'unsupported-executor': {
+			executor: 'shared-iterations',
+			iterations: 1,
+			exec: 'testUnsupportedExecutor'
+		}
+	}
+}
+
+export function testGetCurrentStageIndex() {
+	describe('getCurrentStageIndex', () => {
+		describe('returns the first stage when is in t0', () => {
+			expect(getCurrentStageIndex()).to.be.equal(0)
+		})
+
+		sleep(1.2)
+
+		describe('returns the next stage if the iteration exceedes the expected duration', () => {
+			expect(getCurrentStageIndex()).to.be.equal(1)
+		})
+
+		sleep(1)
+
+		describe('returns the last stage when the iteration exceedes the total expected duration', () => {
+			expect(getCurrentStageIndex()).to.be.equal(1)
+		})
+	})
+}
+
+export function testTagWithCurrentStageIndex() {
+	describe('tagWithCurrentStageIndex', () => {
+		describe('tags with the current stage', () => {
+			tagWithCurrentStageIndex()
+			expect(exec.vu.tags['stage']).to.be.equal(`${exec.scenario.iterationInTest}`)
+		})
+
+		// it forces to get only two iterations
+		sleep(1)
+	})
+}
+
+export function testTagWithRampUpProfileWhenOnlyOne() {
+  describe('tagWithCurrentStageProfile', () => {
+		describe(`tags with ramp-up profile when only one stage`, () => {
+			tagWithCurrentStageProfile()
+			expect(exec.vu.tags['stage_profile']).to.be.equal('ramp-up')
+		})
+	})
+}
+
+export function testTagWithRampUp() {
+  describe('tagWithCurrentStageProfile', () => {
+		describe(`tags with ramp-up profile when the current stage has a target greater than previous`, () => {
+			if (exec.vu.iterationInScenario !== 1) {
+				return
+			}
+			tagWithCurrentStageProfile()
+			expect(exec.vu.tags['stage_profile']).to.be.equal('ramp-up')
+		})
+		sleep(0.1)
+	})
+}
+
+export function testTagWithSteady() {
+  describe('tagWithCurrentStageProfile', () => {
+		describe(`tags with steady profile when the current stage has the same target of the previous`, () => {
+			if (exec.vu.iterationInScenario !== 1) {
+				return
+			}
+			tagWithCurrentStageProfile()
+			expect(exec.vu.tags['stage_profile']).to.be.equal('steady')
+		})
+		sleep(0.1)
+	})
+}
+
+export function testTagWithRampDown() {
+describe('tagWithCurrentStageProfile', () => {
+	describe(`tags with ramp-down profile when the current stage has a target less than previous`, () => {
+		if (exec.vu.iterationInScenario !== 1) {
+			return
+		}
+		tagWithCurrentStageProfile()
+		expect(exec.vu.tags['stage_profile']).to.be.equal('ramp-down')
+	})
+	sleep(0.1)
+})
+}
+
+export function testUnsupportedExecutor() {
+	describe('throw Error if the executor is not supported', () => {
+		describe('getCurrentStageIndex', () => {
+			expect(getCurrentStageIndex).to.throw()
+		})
+		describe('tagWithCurrentStageIndex', () => {
+			expect(tagWithCurrentStageIndex).to.throw()
+		})
+		describe('tagWithCurrentStageProfile', () => {
+			expect(tagWithCurrentStageProfile).to.throw()
+		})
+	})
+}
+
+export function testParseDuration() {
+	describe('parseDuration', () => {
+		let testcase = '1d5h31m20s9ms'
+		describe(testcase, () => {
+			expect(parseDuration(testcase)).to.be.equal(((86400+18000+1860+20)*1000)+9)
+		})
+
+		testcase = '5.2h'
+		describe(testcase, () => {
+			expect(parseDuration(testcase)).to.be.equal(18720*1000)
+		})
+
+		testcase = '1d5.2h31m20s9ms'
+		describe(testcase, () => {
+			expect(parseDuration(testcase)).to.be.equal(((86400+18720+1860+20)*1000)+9)
+		})
+
+		// ms is the maximum precision so this case is truncated
+		testcase = '9.3ms'
+		describe(testcase, () => {
+			expect(parseDuration(testcase)).to.be.equal(9)
+		})
+
+		testcase = '1531209'
+		describe(testcase, () => {
+			expect(parseDuration(testcase)).to.be.equal(1531209)
+		})
+
+		testcase = '9.h1.s'
+		describe(testcase, () => {
+			expect(parseDuration(testcase)).to.be.equal(32401*1000)
+		})
+
+		testcase = '9.h1.s'
+		describe(testcase, () => {
+			expect(parseDuration(testcase)).to.be.equal(32401*1000)
+		})
+
+		testcase = '1s12'
+		describe(testcase, () => {
+			expect(parseDuration(testcase)).to.be.equal(1012)
+		})
+
+		testcase = '1h-1s'
+		describe(testcase, () => {
+			expect(parseDuration(testcase)).to.be.equal(3601*1000)
+		})
+
+		testcase = '-1h 1s'
+		describe(testcase, () => {
+			expect(parseDuration(testcase)).to.be.equal(3601*1000)
+		})
+
+		testcase = '0'
+		describe(testcase, () => {
+			expect(parseDuration(testcase)).to.be.equal(0)
+		})
+
+		testcase = '0s'
+		describe(testcase, () => {
+			expect(parseDuration(testcase)).to.be.equal(0)
+		})
+
+		testcase = '1s 1s 1s'
+		describe(testcase, () => {
+			expect(() => { return parseDuration(testcase) }).to.throw()
+		})
+
+		testcase = '1w'
+		describe(testcase, () => {
+			expect(() => { return parseDuration(testcase) }).to.throw()
+		})
+
+		testcase = ''
+		describe(testcase, () => {
+			expect(() => { return parseDuration(testcase) }).to.throw()
+		})
+})
+}