ΦΕΚ 56/1836 (in Greek)
The first law of the contemporary Greek State about measures and weights which was published in 1836. Introduction of the metric system.

The law includes the relationship of the Royal stremma or simply stremma (1 stremma=1000 m²) with the old Peloponnisian stremma or according to others old Turkish stremma (Peloponnisian stremma=1.27 Royal stemmata).

In the same document the oka is defined as 1280 gr: 1 Royal Mna=1500 Royal drachmas (gramme) ie. 468 3/4 drams and therefore 400 drams=1 oka= 1280 Royal drachmas or gramme.

All the old units were officially abolished in March 31, 1959 (ΦΕΚ 131 Α/1959).

ΦΕΚ 115 B/1959 (in Greek)
The relationship of the pichys with meter.

ΦΕΚ 131 Α/1959 (in Greek)
The law introduces the mandatory use of the International System of Units (SI). All the old units are officially abolished.

ΦΕΚ 191 A/1969 (in Greek)
The mandatory use of the litre for the liquid fuel trade is introduced.

ΦΕΚ 112 A/1978 (in Greek)
Encoding in a single text the current provisions relating to the introduction in Greece of the International System of Units.

Since 1994, when Hellenic Institute of Metrolgy (EIM) was established, all the national primary unit standards are maintained and realized by EIM (ΦΕΚ 139 Α/1994 ).

ΦΕΚ 261 Α/1999 (in Greek)
Law No. 2763.  Ratification of the Meter Convention 

DIRECTIVE 2004/22/EC
Directive 2004/22/EC of the European Parliament on measuring instruments.