PS: there is also an English version of the respective WP page
https://en.wikipedia.org/wiki/1992_Colombian_energy_crisis
It has an interesting statement:
Of Colombia's 1,024 municipalities, 1,000 declined to change time zones and took months to come into effect.the Spanish version in WP makes no sense when it says:
La medida conocida como "Hora Gaviria" comenzó a las 12:00 AM del 2 de mayo de 1992. Mil alcaldes municipales de los 1.024 que tenía el país en ese momento se negaron a cambiar a la zona horaria y solo se ajustaron a la medida diez meses despuésy solo se ajustaron a la medida diez meses después = and they were only fitted to the measure ten months later. because 10 months after may 1992 we are in March 1993, and by that time the measure had already ended.
It will be hard to research which parts of the country adopted
the 1992 time shift at which point. This being after 1970, TZ
should in principle represent the division of the country into
areas with different time practice.
TZ has for Colombia a single period with time zone 4h west.
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule CO 1992 only - May 3 0:00 1:00 -
Rule CO 1993 only - Apr 4 0:00 0 -
I think the end date 4 April is wrong, it should be 6 February 24h or 7 February 0h
The time shift was called Hora Gaviria, and caused by shortage of electricity in connection with El Niño .
Source: DECRETO 267 DE 1993
https://www.suin-juriscol.gov.co/viewDocument.asp?ruta=Decretos/1061335
Artículo 1° Adoptar como hora legal en el territorio de la República, la del Tiempo Universal Coordinado, UTC, disminuido en cinco (5) horas.
Artículo 2° El cambio de hora se hará efectivo a las veinticuatro horas del día 6 de febrero del presente año.
There is also a newspaper article https://www.eltiempo.com/archivo/documento/MAM-32922
of 4 feb 1993, but the text is less clear to my limited understanding of Spanish.See also https://es.wikipedia.org/wiki/Crisis_energ%C3%A9tica_de_1992_en_Colombia