timestamp

问题 Scenario: An record was entered into the database. I am trying to figure out the following equations: How to get the number of hours since the record was added. How to get how many hours are left until midnight since the record was added. Given these times: Date / Time: 2012-08-22 20:11:20 Time Stamp: 1345684280 Midnight Tonight: 2012-08-23 00:00:00 Midnight Time Stamp: 1345698000 I feel like I'm on the right track. Just need some proper math to do the calculations? I am horrible at math. Any

问题 I am trying to add Data to Cloud Firestore via the REST API (https://developers.google.com/apis-explorer/#search/firestore/firestore/v1beta1/firestore.projects.databases.documents.createDocument) I am able to create a new Document with e.g. an Integer Value, so the connection and the syntax seems to be ok. In the next step I want to add the server side timestamp to the document. Because I make the POST-Request from an ESP32 and the time is not available. The Request-Body looks like: { "fields

问题 Why Timestamp((long)-62135596800000L) return 0001-01-03 00:00:00 , but must return 0001-01-01 00:00:00 ? This service show correct Timestamp here 回答1: -62135596800000 is 0001-01-03 00:00:00.0 Because by default java uses Julian calendar for dates before October 15, 1582. The website you are using, uses javascript which uses extrapolated, or proleptic, Gregorian calendar for all dates. From javascript specification ECMAScript uses an extrapolated Gregorian system to map a day number to a year

问题 I have two timestamps in character form that I want to convert to a POSIX format in R. The timestamps are: 1: "2013-03-30 17:45:00" 2: "2013-03-31 02:05:00" The first one converts fine, the second one gives me NA . The timestamps are downloaded as characters from an SQL server . Anyone have any ideas what is going wrong? I don't have the reputation to attach a screenshot, so a screenshot of my R console showing the result is provided here: http://emillarsen.com/r%20console.jpg 回答1: It looks

问题 As per MongoDB official docs, it states that: ObjectId values consists of 12-bytes, where the first four bytes are a timestamp that reflect the ObjectId’s creation, specifically: a 4-byte value representing the seconds since the Unix epoch, a 3-byte machine identifier, a 2-byte process id, and a 3-byte counter, starting with a random value. I'm just wondering what's gonna happen on Tue, 19 Jan 2038 03:14:08 GMT when the unix time will be equal to 2147483648 which doesn't fit the 4-byte

问题 I have table with timestamps in ms stored in it. I want to convert those timestamps in a human readable form. Here is a sample output of my table: SELECT date raw, strftime('%d-%m-%Y', (date/1000)) as_string FROM my_table +-----------------+--------------+ | raw | as_string | +-----------------+--------------+ | 1444687200000 | 06-47-3950 | +-----------------+--------------+ ... ... ... +-----------------+--------------+ As you can see, the date as string is quite strange ( 06-47-3950 ). How

问题 We have dates stored as a unix timestamp. To allow a user to search for a certain date - based on his timezone-setting, we used to convert that timestamp inside the query, to make sure a search for "2012-05-03" will not find results of the prior / next day depending on which timezone the user has setup. i.e. if a date is stored as 2012-05-03 23:00 (UTC) A user with the proper timezone offset searching for 2012-05-04 should find this entry. This is done like this at the moment: CONVERT_TZ(FROM

问题 I have a column update_date in a table and type is timestamp. I set the deault value by using phpmyadmin drop down menu to CURRENT_TIMESTAMP. But later when ever I run sql UPDATE x SET ... it updates the timestamp column if only there is a changes in any of the columns. What I would like to achieve is that whether there is a change or not set the current time everytime the update sql runs. Is there any way of doing it in the mysql or I need to set the update_date explicitly every time the

问题 This consists of two questions: Is MySQL's timestamp field really faster than datetime field in "order by" query? If the answer to above question is yes, how much faster it could be? Supposed in a table of 100 million rows and frequently sort a bunch of 100-200k rows based on timestamp field inside MySQL, will the sort time improvement be offseted by converting timestamp to readable string format in outside program? 回答1: The easiest way to find out is to write a unit test, and actually get

问题 I want to get year-month-day hour:minute:second.fraction(2 digits), if I use "%Y-%m-%d %H:%M:%S.%f", I got almost what I want exception for the fraction( last part ) of seconds, it's showing 6 digits on my Windows XP, I don't know how to get 2 digits only, any idea? 回答1: Boost.DateTime (upon which Boost.Log relies) doesn't seem to support specialized fractional seconds formatting, so the only way to do that would be to write your own custom attribute formatter, or (the easier, but less nice