🔮 Demo

📜 Code

datepickerWithNavButtons.html

<template>
    <lightning-card hide-header="true">
        <div class="slds-card__body slds-card__body_inner">
            <div class="slds-grid">
                <div class="slds-col slds-grow-none">
                    <lightning-button-icon icon-name="utility:chevronleft" alternative-text="Previous" title="Previous"
                        data-direction="Previous" onclick={changeDate}>
                    </lightning-button-icon>
                </div>
                <div class="slds-col slds-grow-none slds-p-horizontal_x-small">
                    <lightning-input type="date" variant="label-hidden" value={selectedDate}
                        onchange={handleDateChange}>
                    </lightning-input>
                </div>
                <div class="slds-col slds-grow-none">
                    <lightning-button-icon icon-name="utility:chevronright" alternative-text="Next" title="Next"
                        data-direction="Next" onclick={changeDate}>
                    </lightning-button-icon>
                </div>
            </div>

            <div class="slds-m-top_small">
                Selected Date ➡️ <lightning-formatted-date-time value={selectedDate}></lightning-formatted-date-time>
            </div>
        </div>
    </lightning-card>
</template>

datepickerWithNavButtons.js

import { LightningElement, track } from 'lwc';
export default class DatepickerWithNavButtons extends LightningElement {
    @track selectedDate;

    connectedCallback() {
        //set today's date as default value of the datepicker
        this.setCalendarStartDate();
    }

    // Method to set the initial value for the selectedDate property
    setCalendarStartDate() {
        // Set the selectedDate to the current date in the datepicker's desired format
        this.selectedDate = this.formatToDatePickerValue(new Date());
    }

    // Event handler for changing the date based on previous & next button clicks
    changeDate(event){
        // Extract the direction from the clicked button's data-direction attribute
        let direction = event.currentTarget.dataset.direction;

        // Create a new Date object based on the current selectedDate
        let currentDate = new Date(this.selectedDate);

        // Adjust the date based on the direction (Previous or Next)
        if(direction == 'Previous'){
            currentDate.setDate(currentDate.getDate() - 1);
        } else if(direction == 'Next'){
            currentDate.setDate(currentDate.getDate() + 1);
        }

        // Update the selectedDate with the adjusted date
        this.selectedDate = this.formatToDatePickerValue(currentDate);
    }

    // Event handler for handling changes when the user manually changes a date
    handleDateChange(event){
        // Update the selectedDate with the value choosen by the user
        this.selectedDate = event.currentTarget.value;
    }

    // Utility method to format a Date object to the desired date picker value format
    formatToDatePickerValue(dateVal){
        // Convert the Date object to a string in the format YYYY-MM-DD
        return dateVal.toISOString().slice(0, 10);
    }
}

🧩 Components Used

• Lightning Input - Type Date - https://developer.salesforce.com/docs/component-library/bundle/lightning-input/example

• Lightning Button Icon - https://developer.salesforce.com/docs/component-library/bundle/lightning-button-icon/example