#Groovy, 75 73 bytes

t=System.&nanoTime
s=t()
(-1000..1e3).each{println it}
print((t()-s)/1e6)

Thanks to jaxad0127 for saving 2 bytes!

Try it here !

Groovy, 75 73 bytes

t=System.&nanoTime
s=t()
(-1000..1e3).each{println it}
print((t()-s)/1e6)

Thanks to jaxad0127 for saving 2 bytes!

Try it here !

#Groovy, 75 73 bytes

t=System.&nanoTime
s=t()
(-1000..1e3).each{println it}
print((t()-s)/1e6)

Thanks to jaxad0127 for saving 2 bytes!

Try it here !

#Groovy, 75 73 bytes

t=System.&nanoTime
s=t()
(-1000..1e3).each{println it}
print((t()-s)/1e6)

Thanks to jaxad0127 for saving 2 bytes!

Try it here !

#Groovy, 75 bytes

t=System.&currentTimeMillis
s=t()
(-1000..1e3).each{println it}
print t()-s

currentTimeMillis. Sigh.

Try it here !

#Groovy, 75 73 bytes

t=System.&nanoTime
s=t()
(-1000..1e3).each{println it}
print((t()-s)/1e6)

Thanks to jaxad0127 for saving 2 bytes!

Try it here !