JQ: Transform UNIX Timestamp to Datetime - jq

Question

I use actually JQ1.5 under a Windows 10 environment to transform several json files for an import to a MS SQL database. Part of the data are formatted in UNIX timestamp and I need to transform those data to ISO 8601 Format.
Following command i use actually for the transformation of the data:
jq '
[
{ nid, title, nights, zone: .zones[0].title} +
(.sails[] | { sails_nid: .nid, arrival, departure } ) +
(.sails[].cabins[] |
{ cabintype: .cabinType.kindName,
cabinid: .cabinType.nid,
catalogPrice,
discountPrice,
discountPercentage,
currency
}
)
]
' C:\Import\dreamlines_details.json > C:\Import\import_sails.json
Arrival and departure are the data that are in Unix time formated.
Data:
[
{
"nid": 434508,
"title": "Die schönsten Orte unserer Welt",
"nights": 121,
"zone": "Weltreise",
"sails_nid": 434516,
"arrival": 1525644000,
"departure": 1515193200,
"cabintype": "Innenkabine",
"cabinid": 379723,
"catalogPrice": 17879,
"discountPrice": 9519,
"discountPercentage": 0.4675876726886291,
"currency": "EUR"
},
{
"nid": 434508,
"title": "Die schönsten Orte unserer Welt",
"nights": 121,
"zone": "Weltreise",
"sails_nid": 434516,
"arrival": 1525644000,
"departure": 1515193200,
"cabintype": "Innenkabine",
"cabinid": 379730,
"catalogPrice": 18599,
"discountPrice": 10239,
"discountPercentage": 0.44948653153395346,
"currency": "EUR"
}
]
I experimented with built in operator "todate" and "strftime". But get only parsing Errors.

Answer 1

Use todateiso8601 function:
jq '.[].arrival |= todateiso8601 | .[].departure |= todateiso8601' C:\Import\import_sails.json
The output (for your input fragment):
[
{
"nid": 434508,
"title": "Die schönsten Orte unserer Welt",
"nights": 121,
"zone": "Weltreise",
"sails_nid": 434516,
"arrival": "2018-05-06T22:00:00Z",
"departure": "2018-01-05T23:00:00Z",
"cabintype": "Innenkabine",
"cabinid": 379723,
"catalogPrice": 17879,
"discountPrice": 9519,
"discountPercentage": 0.4675876726886291,
"currency": "EUR"
},
{
"nid": 434508,
"title": "Die schönsten Orte unserer Welt",
"nights": 121,
"zone": "Weltreise",
"sails_nid": 434516,
"arrival": "2018-05-06T22:00:00Z",
"departure": "2018-01-05T23:00:00Z",
"cabintype": "Innenkabine",
"cabinid": 379730,
"catalogPrice": 18599,
"discountPrice": 10239,
"discountPercentage": 0.44948653153395346,
"currency": "EUR"
}
]

Answer 2

I had a similar problem when parsing output of Perforce (with -Mj option),
but the epoch times were strings, not numbers.
$ p4 -z tag -Mj labels -e "test_build" | jq '.'
{
"Access": "1581356898",
"Description": "Created by p4build.\n",
"Options": "unlocked noautoreload",
"Owner": "p4build",
"Update": "1580936739",
"label": "test_build"
}
Adding tonumber into the filter fixes it:
$ p4 -z tag -Mj labels -e "test_build" > test.json
$ jq -s '.[].Access |= (tonumber | todateiso8601) | .[].Update |= (tonumber | todateiso8601)' test.json
[
{
"Access": "2020-02-10T17:48:18Z",
"Description": "Created by p4build.\n",
"Options": "unlocked noautoreload",
"Owner": "p4build",
"Update": "2020-02-05T21:05:39Z",
"label": "test_build"
}
]