Serbian word „leto” means both „summer” and „year”. The word comes from Proto-Slavic *lěto, which comes from Proto-Indo-European *leh₁tom. Cognate with Ukrainian „літо” ‎(lito) meaning „summer”, Belarusian „слецiць” ‎(sljecicʹ) meaning „to warm” and „слетный” ‎(sljetnyj) meaning „warmish”, Bulgarian „лято” ‎(ljato) meaning „summer”, Russian „лето” (leto) meaning „summer, year”, Slovene „poletje” meaning „summer”, Czech „léto” meaning „summer”, Slovak „leto” meaning „summer”, Polish „lato” meaning „summer”, and Upper and Lower Sorbian „lěto” meaning „year”.

Possibly also cognate with Old Gutnish „ladigh” meaning „spring” and dialectal Swedish „låding, låing” meaning „spring”, and with Irish „lá” ‎meaning „day”.

Alfons Mucha – Lato